@Article{Erskine2018,
  Title                    = {Real-time spectral characterization of a photon pair source using a chirped supercontinuum seed},
  Author                   = {Erskine, J. and England, D. and Kupchak, C. and Sussman, B.},
  Journal                  = {Optics Letters},
  Year                     = {2018},
  Number                   = {4},
  Pages                    = {907--910},
  Volume                   = {43},

  __markedentry            = {[paul:]},
  Abstract                 = {Photon pair sources have wide ranging applications in a variety of quantum photonic experiments and protocols. Many of these protocols require well controlled spectral correlations between the two output photons. However, due to low cross-sections, measuring the joint spectral properties of photon pair sources has historically been a challenging and time-consuming task. Here, we present an approach for the real-time measurement of the joint spectral properties of a fiber-based four wave mixing source. We seed the four wave mixing process using a broadband chirped pulse, studying the stimulated process to extract information regarding the spontaneous process. In addition, we compare stimulated emission measurements with the spontaneous process to confirm the technique{\textquoteright}s validity. Joint spectral measurements have taken many hours historically and several minutes with recent techniques. Here, measurements have been demonstrated in 5--30 s depending on resolution, offering substantial improvement. Additional benefits of this approach include flexible resolution, large measurement bandwidth, and reduced experimental overhead. {\copyright} 2018 Optical Society of America.},
  Affiliation              = {Department of Physics, University of Ottawa, 598 King Edward, Ottawa, ON, Canada; National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada},
  Document_type            = {Article},
  Doi                      = {10.1364/OL.43.000907},
  Source                   = {Scopus},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042081705&doi=10.1364%2fOL.43.000907&partnerID=40&md5=d836eddded287aa89aedf00ac3d34488}
}

Photon pair sources have wide ranging applications in a variety of quantum photonic experiments and protocols. Many of these protocols require well controlled spectral correlations between the two output photons. However, due to low cross-sections, measuring the joint spectral properties of photon pair sources has historically been a challenging and time-consuming task. Here, we present an approach for the real-time measurement of the joint spectral properties of a fiber-based four wave mixing source. We seed the four wave mixing process using a broadband chirped pulse, studying the stimulated process to extract information regarding the spontaneous process. In addition, we compare stimulated emission measurements with the spontaneous process to confirm the technique\textquoterights validity. Joint spectral measurements have taken many hours historically and several minutes with recent techniques. Here, measurements have been demonstrated in 5–30 s depending on resolution, offering substantial improvement. Additional benefits of this approach include flexible resolution, large measurement bandwidth, and reduced experimental overhead. © 2018 Optical Society of America.

@Conference{Erskine2018a,
  Title                    = {Real-time spectral characterization of a photon pair source using a chirped supercontinuum seed},
  Author                   = {Erskine, J. and England, D.G. and Kupchak, C. and Sussman, B.J.},
  Year                     = {2018},
  Volume                   = {Part F93-CLEO_QELS 2018},

  __markedentry            = {[paul:]},
  Abstract                 = {We perform joint spectral intensity measurements by studying stimulated four wave mixing in a birefringent fiber photon pair source. Seeding the process with a chirped supercontinuum beam, measurements are acquired in as little as 5 s. {\copyright} OSA 2018.},
  Affiliation              = {National Research Council, Ottawa, Canada; Department of Physics, University of Ottawa, Ottawa, Canada},
  Document_type            = {Conference Paper},
  Doi                      = {10.1364/CLEO_QELS.2018.FM4G.6},
  Journal                  = {Optics InfoBase Conference Papers},
  Page_count               = {2},
  Source                   = {Scopus},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048935944&doi=10.1364%2fCLEO_QELS.2018.FM4G.6&partnerID=40&md5=79b6888893bc3a7972ae24409ae1b063}
}

We perform joint spectral intensity measurements by studying stimulated four wave mixing in a birefringent fiber photon pair source. Seeding the process with a chirped supercontinuum beam, measurements are acquired in as little as 5 s. © OSA 2018.

@Article{Forbes2018,
  Title                    = {{Quantum-beat photoelectron-imaging spectroscopy of Xe in the VUV}},
  Author                   = {Forbes, Ruaridh and Makhija, Varun and Underwood, Jonathan G. and Stolow, Albert and Wilkinson, Iain and Hockett, Paul and Lausten, Rune},
  Journal                  = {Physical Review A},
  Year                     = {2018},

  Month                    = jun,
  Number                   = {6},
  Pages                    = {063417},
  Volume                   = {97},

  __markedentry            = {[paul:]},
  Abstract                 = {Time-resolved pump-probe measurements of Xe, pumped at 133{\~{}}nm and probed at 266{\~{}}nm, are presented. The pump pulse prepared a long-lived hyperfine wavepacket, in the Xe {\$}5p{\^{}}5({\^{}}2P{\^{}}{\{}\backslashcirc{\}}{\_}{\{}1/2{\}})6s{\~{}}{\^{}}2[1/2]{\^{}}{\{}\backslashcirc{\}}{\_}1{\$} manifold ({\$}E={\$}77185 cm{\$}{\^{}}{\{}-1{\}}={\$}9.57 eV). The wavepacket was monitored via single-photon ionization, and photoelectron images measured. The images provide angle- and time-resolved data which, when obtained over a large time-window (900{\~{}}ps), constitute a precision quantum beat spectroscopy measurement of the hyperfine state splittings. Additionally, analysis of the full photoelectron image stack provides a quantum beat imaging modality, in which the Fourier components of the photoelectron images correlated with specific beat components can be obtained. This may also permit the extraction of isotope-resolved photoelectron images in the frequency domain, in cases where nuclear spins (hence beat components) can be uniquely assigned to specific isotopes (as herein), and also provides phase information. The information content of both raw, and inverted, image stacks is investigated, suggesting the utility of the Fourier analysis methodology in cases where images cannot be inverted.},
  Archiveprefix            = {arXiv},
  Arxivid                  = {1803.01081},
  Doi                      = {10.1103/PhysRevA.97.063417},
  Eprint                   = {1803.01081},
  ISSN                     = {2469-9926},
  Timestamp                = {2018.07.12},
  Url                      = {http://arxiv.org/abs/1803.01081}
}

Time-resolved pump-probe measurements of Xe, pumped at 133\ nm and probed at 266\ nm, are presented. The pump pulse prepared a long-lived hyperfine wavepacket, in the Xe $}5p{^}5({^}2P{^}{\{}i̧rc{\}}{_}{\{}1/2{\}})6s{\ {}}{^}2[1/2]{^}{\{}i̧rc{\}}{_}1{$ manifold ($}E={$77185 cm$}{^}{\{}-1{\}}={$9.57 eV). The wavepacket was monitored via single-photon ionization, and photoelectron images measured. The images provide angle- and time-resolved data which, when obtained over a large time-window (900\ ps), constitute a precision quantum beat spectroscopy measurement of the hyperfine state splittings. Additionally, analysis of the full photoelectron image stack provides a quantum beat imaging modality, in which the Fourier components of the photoelectron images correlated with specific beat components can be obtained. This may also permit the extraction of isotope-resolved photoelectron images in the frequency domain, in cases where nuclear spins (hence beat components) can be uniquely assigned to specific isotopes (as herein), and also provides phase information. The information content of both raw, and inverted, image stacks is investigated, suggesting the utility of the Fourier analysis methodology in cases where images cannot be inverted.

@Book{Hockett2018,
  Title                    = {{Quantum Metrology with Photoelectrons, Volume 2 {A}pplications and advances}},
  Author                   = {Hockett, Paul},
  Publisher                = {IOP Publishing},
  Year                     = {2018},

  __markedentry            = {[paul:]},
  Comment                  = {Website: https://osf.io/q2v3g},
  Doi                      = {10.1088/978-1-6817-4688-3},
  ISBN                     = {978-1-6817-4688-3},
  Timestamp                = {2018.07.12},
  Url                      = {http://iopscience.iop.org/book/978-1-6817-4688-3}
}

@Book{Hockett2018a,
  Title                    = {{Quantum Metrology with Photoelectrons, Volume 1 {F}oundations}},
  Author                   = {Hockett, Paul},
  Publisher                = {IOP Publishing},
  Year                     = {2018},

  __markedentry            = {[paul:]},
  Comment                  = {Website: https://osf.io/q2v3g},
  Doi                      = {10.1088/978-1-6817-4684-5},
  ISBN                     = {978-1-6817-4684-5},
  Timestamp                = {2018.07.12},
  Url                      = {http://iopscience.iop.org/book/978-1-6817-4684-5}
}

@Article{Bustard2017,
  Title                    = {Quantum frequency conversion with ultra-broadband tuning in a Raman memory},
  Author                   = {Bustard, P.J. and England, D.G. and Heshami, K. and Kupchak, C. and Sussman, B.J.},
  Journal                  = {Physical Review A},
  Year                     = {2017},
  Number                   = {5},
  Volume                   = {95},

  __markedentry            = {[paul:]},
  Abstract                 = {Quantum frequency conversion is a powerful tool for the construction of hybrid quantum photonic technologies. Raman quantum memories are a promising method of conversion due to their broad bandwidths. Here we demonstrate frequency conversion of THz-bandwidth, fs-duration photons at the single-photon level using a Raman quantum memory based on the rotational levels of hydrogen molecules. We shift photons from 765 nm to wavelengths spanning from 673 to 590 nm - an absolute shift of up to 116 THz. We measure total conversion efficiencies of up to 10% and a maximum signal-to-noise ratio of 4.0(1):1, giving an expected conditional fidelity of 0.75, which exceeds the classical threshold of 2/3. Thermal noise could be eliminated by cooling with liquid nitrogen, giving noiseless conversion with wide tunability in the visible and infrared. {\copyright} 2017 American Physical Society.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada; Department of Physics, University of Ottawa, Ottawa, ON, Canada},
  Art_number               = {053816},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.95.053816},
  Source                   = {Scopus},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026811427&doi=10.1103%2fPhysRevA.95.053816&partnerID=40&md5=bb46367e7043844ddf47d7922a010887}
}

Quantum frequency conversion is a powerful tool for the construction of hybrid quantum photonic technologies. Raman quantum memories are a promising method of conversion due to their broad bandwidths. Here we demonstrate frequency conversion of THz-bandwidth, fs-duration photons at the single-photon level using a Raman quantum memory based on the rotational levels of hydrogen molecules. We shift photons from 765 nm to wavelengths spanning from 673 to 590 nm - an absolute shift of up to 116 THz. We measure total conversion efficiencies of up to 10% and a maximum signal-to-noise ratio of 4.0(1):1, giving an expected conditional fidelity of 0.75, which exceeds the classical threshold of 2/3. Thermal noise could be eliminated by cooling with liquid nitrogen, giving noiseless conversion with wide tunability in the visible and infrared. © 2017 American Physical Society.

@Conference{England2017,
  Title                    = {A quantum light-matter beamsplitter in diamond},
  Author                   = {England, D.G. and Heshami, K. and Bustard, P.J. and Sussman, B.J. and Fisher, K.A.G. and MacLean, J.-P.W. and Resch, K.J.},
  Year                     = {2017},
  Volume                   = {Part F42-CLEO_QELS 2017},

  __markedentry            = {[paul:]},
  Abstract                 = {A quantum memory can be viewed as a light-matter beam-splitter, mapping a photon to a superposition of the output optical mode and stored mode. We use this mechanism to demonstrate non-classical onephoton and two-photon interference. {\copyright} OSA 2017.},
  Affiliation              = {National Research Council, Ottawa, Canada; Institute for Quantum Computing, University of Waterloo, Waterloo, Canada},
  Document_type            = {Conference Paper},
  Doi                      = {10.1364/CLEO_QELS.2017.FM2E.5},
  Journal                  = {Optics InfoBase Conference Papers},
  Page_count               = {2},
  Source                   = {Scopus},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85020685777&doi=10.1364%2fCLEO_QELS.2017.FM2E.5&partnerID=40&md5=54c164317411ed8771f8961504153465}
}

A quantum memory can be viewed as a light-matter beam-splitter, mapping a photon to a superposition of the output optical mode and stored mode. We use this mechanism to demonstrate non-classical onephoton and two-photon interference. © OSA 2017.

@Article{Fisher2017,
  Title                    = {Storage of polarization-entangled {THz}-bandwidth photons in a diamond quantum memory},
  Author                   = {Fisher, K.A.G. and England, D.G. and MacLean, J.-P.W. and Bustard, P.J. and Heshami, K. and Resch, K.J. and Sussman, B.J.},
  Journal                  = {Physical Review A},
  Year                     = {2017},
  Number                   = {1},
  Volume                   = {96},

  __markedentry            = {[paul:]},
  Abstract                 = {Bulk diamond phonons have been shown to be a versatile platform for the generation, storage, and manipulation of high-bandwidth quantum states of light. Here we demonstrate a diamond quantum memory that stores, and releases on demand, an arbitrarily polarized $\sim$250 fs duration photonic qubit. The single-mode nature of the memory is overcome by mapping the two degrees of polarization of the qubit, via Raman transitions, onto two spatially distinct optical phonon modes located in the same diamond crystal. The two modes are coherently recombined upon retrieval and quantum process tomography confirms that the memory faithfully reproduces the input state with average fidelity 0.784$\pm$0.004 with a total memory efficiency of (0.76$\pm$0.03)%. In an additional demonstration, one photon of a polarization-entangled pair is stored in the memory. We report that entanglement persists in the retrieved state for up to 1.3 ps of storage time. These results demonstrate that the diamond phonon platform can be used in concert with polarization qubits, a key requirement for polarization-encoded photonic processing. {\copyright} 2017 American Physical Society.},
  Affiliation              = {Institute for Quantum Computing, Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON, Canada; National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada; Department of Physics, University of Ottawa, Ottawa, ON, Canada; Department of Physics, Centre for Quantum Information and Quantum Control, Institute for Optical Sciences, University of Toronto, 60 St. George Street, Toronto, ON, Canada},
  Art_number               = {012324},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.96.012324},
  Source                   = {Scopus},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85026832050&doi=10.1103%2fPhysRevA.96.012324&partnerID=40&md5=8e76ba081c99132fe77f96b2483e2bd5}
}

Bulk diamond phonons have been shown to be a versatile platform for the generation, storage, and manipulation of high-bandwidth quantum states of light. Here we demonstrate a diamond quantum memory that stores, and releases on demand, an arbitrarily polarized $∼$250 fs duration photonic qubit. The single-mode nature of the memory is overcome by mapping the two degrees of polarization of the qubit, via Raman transitions, onto two spatially distinct optical phonon modes located in the same diamond crystal. The two modes are coherently recombined upon retrieval and quantum process tomography confirms that the memory faithfully reproduces the input state with average fidelity 0.784$±$0.004 with a total memory efficiency of (0.76$±$0.03)%. In an additional demonstration, one photon of a polarization-entangled pair is stored in the memory. We report that entanglement persists in the retrieved state for up to 1.3 ps of storage time. These results demonstrate that the diamond phonon platform can be used in concert with polarization qubits, a key requirement for polarization-encoded photonic processing. © 2017 American Physical Society.

@Article{Forbes2017,
  Title                    = {Time-resolved multi-mass ion imaging: Femtosecond UV-VUV pump-probe spectroscopy with the PImMS camera},
  Author                   = {Forbes, R. and Makhija, V. and Veyrinas, K. and Stolow, A. and Lee, J.W.L. and Burt, M. and Brouard, M. and Vallance, C. and Wilkinson, I. and Lausten, R. and Hockett, P.},
  Journal                  = {Journal of Chemical Physics},
  Year                     = {2017},
  Number                   = {1},
  Volume                   = {147},

  Abstract                 = {The Pixel-Imaging Mass Spectrometry (PImMS) camera allows for 3D charged particle imaging measurements, in which the particle time-of-flight is recorded along with (x, y) position. Coupling the PImMS camera to an ultrafast pump-probe velocity-map imaging spectroscopy apparatus therefore provides a route to time-resolved multi-mass ion imaging, with both high count rates and large dynamic range, thus allowing for rapid measurements of complex photofragmentation dynamics. Furthermore, the use of vacuum ultraviolet wavelengths for the probe pulse allows for an enhanced observation window for the study of excited state molecular dynamics in small polyatomic molecules having relatively high ionization potentials. Herein, preliminary time-resolved multi-mass imaging results from C2F3I photolysis are presented. The experiments utilized femtosecond VUV and UV (160.8 nm and 267 nm) pump and probe laser pulses in order to demonstrate and explore this new time-resolved experimental ion imaging configuration. The data indicate the depth and power of this measurement modality, with a range of photofragments readily observed, and many indications of complex underlying wavepacket dynamics on the excited state(s) prepared. © 2017 Crown.},
  Art_number               = {013911},
  Document_type            = {Article},
  Doi                      = {10.1063/1.4978923},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85017137986&doi=10.1063%2f1.4978923&partnerID=40&md5=ad133dc43109bff535caeaa6fd29d5d6}
}

The Pixel-Imaging Mass Spectrometry (PImMS) camera allows for 3D charged particle imaging measurements, in which the particle time-of-flight is recorded along with (x, y) position. Coupling the PImMS camera to an ultrafast pump-probe velocity-map imaging spectroscopy apparatus therefore provides a route to time-resolved multi-mass ion imaging, with both high count rates and large dynamic range, thus allowing for rapid measurements of complex photofragmentation dynamics. Furthermore, the use of vacuum ultraviolet wavelengths for the probe pulse allows for an enhanced observation window for the study of excited state molecular dynamics in small polyatomic molecules having relatively high ionization potentials. Herein, preliminary time-resolved multi-mass imaging results from C2F3I photolysis are presented. The experiments utilized femtosecond VUV and UV (160.8 nm and 267 nm) pump and probe laser pulses in order to demonstrate and explore this new time-resolved experimental ion imaging configuration. The data indicate the depth and power of this measurement modality, with a range of photofragments readily observed, and many indications of complex underlying wavepacket dynamics on the excited state(s) prepared. © 2017 Crown.

@Article{Forbes2017a,
  Title                    = {{Time-resolved multi-mass ion imaging: Femtosecond {UV}-VUV pump-probe spectroscopy with the PImMS camera}},
  Author                   = {Forbes, Ruaridh and Makhija, Varun and Veyrinas, K{\'{e}}vin and Stolow, Albert and Lee, Jason W. L. and Burt, Michael and Brouard, Mark and Vallance, Claire and Wilkinson, Iain and Lausten, Rune and Hockett, Paul},
  Journal                  = {The Journal of Chemical Physics},
  Year                     = {2017},

  Month                    = jul,
  Number                   = {1},
  Pages                    = {013911},
  Volume                   = {147},

  __markedentry            = {[paul:]},
  Abstract                 = {The Pixel-Imaging Mass Spectrometry (PImMS) camera allows for 3D charged particle imaging measurements, in which the particle time-of-flight is recorded along with {\$}(x,y){\$} position. Coupling the PImMS camera to an ultrafast pump-probe velocity-map imaging spectroscopy apparatus therefore provides a route to time-resolved multi-mass ion imaging, with both high count rates and large dynamic range, thus allowing for rapid measurements of complex photofragmentation dynamics. Furthermore, the use of vacuum ultraviolet wavelengths for the probe pulse allows for an enhanced observation window for the study of excited state molecular dynamics in small polyatomic molecules having relatively high ionization potentials. Herein, preliminary time-resolved multi-mass imaging results from C{\$}{\_}2{\$}F{\$}{\_}3{\$}I photolysis are presented. The experiments utilized femtosecond UV and VUV (160.8{\~{}}nm and 267{\~{}}nm) pump and probe laser pulses in order to demonstrate and explore this new time-resolved experimental ion imaging configuration. The data indicates the depth and power of this measurement modality, with a range of photofragments readily observed, and many indications of complex underlying wavepacket dynamics on the excited state(s) prepared.},
  Archiveprefix            = {arXiv},
  Arxivid                  = {1702.00744},
  Doi                      = {10.1063/1.4978923},
  Eprint                   = {1702.00744},
  ISSN                     = {0021-9606},
  Timestamp                = {2018.07.12},
  Url                      = {http://arxiv.org/abs/1702.00744}
}

The Pixel-Imaging Mass Spectrometry (PImMS) camera allows for 3D charged particle imaging measurements, in which the particle time-of-flight is recorded along with $}(x,y){$ position. Coupling the PImMS camera to an ultrafast pump-probe velocity-map imaging spectroscopy apparatus therefore provides a route to time-resolved multi-mass ion imaging, with both high count rates and large dynamic range, thus allowing for rapid measurements of complex photofragmentation dynamics. Furthermore, the use of vacuum ultraviolet wavelengths for the probe pulse allows for an enhanced observation window for the study of excited state molecular dynamics in small polyatomic molecules having relatively high ionization potentials. Herein, preliminary time-resolved multi-mass imaging results from C$}{_}2{$F$}{_}3{$I photolysis are presented. The experiments utilized femtosecond UV and VUV (160.8\ nm and 267\ nm) pump and probe laser pulses in order to demonstrate and explore this new time-resolved experimental ion imaging configuration. The data indicates the depth and power of this measurement modality, with a range of photofragments readily observed, and many indications of complex underlying wavepacket dynamics on the excited state(s) prepared.

@Article{Hockett2017b,
  Title                    = {{Angle-resolved RABBITT: theory and numerics}},
  Author                   = {Hockett, Paul},
  Journal                  = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  Year                     = {2017},

  Month                    = aug,
  Number                   = {15},
  Pages                    = {154002},
  Volume                   = {50},

  __markedentry            = {[paul:]},
  Abstract                 = {{\textcopyright} 2017 IOP Publishing Ltd. Angle-resolved (AR) RABBITT measurements offer a high information content measurement scheme, due to the presence of multiple, interfering, ionization channels combined with a phase-sensitive observable in the form of angle and time-resolved photoelectron interferograms. In order to explore the characteristics and potentials of AR-RABBITT, a perturbative 2-photon model is developed; based on this model, example AR-RABBITT results are computed for model and real systems, for a range of RABBITT schemes. These results indicate some of the phenomena to be expected in AR-RABBITT measurements, and suggest various applications of the technique in photoionization metrology.},
  Archiveprefix            = {arXiv},
  Arxivid                  = {1703.08586},
  Doi                      = {10.1088/1361-6455/aa7887},
  Eprint                   = {1703.08586},
  ISSN                     = {0953-4075},
  Keywords                 = {angle-resolved,atto,photoelectron spectroscopy,photoionization,ultrafast},
  Timestamp                = {2018.07.12},
  Url                      = {http://stacks.iop.org/0953-4075/50/i=15/a=154002?key=crossref.5d6778123ace5e660772ac4533b801a0}
}

© 2017 IOP Publishing Ltd. Angle-resolved (AR) RABBITT measurements offer a high information content measurement scheme, due to the presence of multiple, interfering, ionization channels combined with a phase-sensitive observable in the form of angle and time-resolved photoelectron interferograms. In order to explore the characteristics and potentials of AR-RABBITT, a perturbative 2-photon model is developed; based on this model, example AR-RABBITT results are computed for model and real systems, for a range of RABBITT schemes. These results indicate some of the phenomena to be expected in AR-RABBITT measurements, and suggest various applications of the technique in photoionization metrology.

@Article{Hockett2017,
  Title                    = {Reply to Comment on 'Time delays in molecular photoionization'},
  Author                   = {Hockett, P. and Frumker, E. and Villeneuve, D.M. and Corkum, P.B.},
  Journal                  = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  Year                     = {2017},
  Number                   = {7},
  Volume                   = {50},

  Art_number               = {078003},
  Document_type            = {Letter},
  Doi                      = {10.1088/1361-6455/aa620c},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85016145722&doi=10.1088%2f1361-6455%2faa620c&partnerID=40&md5=0ec8686c1f9399af585ca721b7fbf80c}
}

@Article{Khazali2017,
  Title                    = {Single-photon source based on Rydberg exciton blockade},
  Author                   = {Khazali, M. and Heshami, K. and Simon, C.},
  Journal                  = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  Year                     = {2017},
  Number                   = {21},
  Volume                   = {50},

  __markedentry            = {[paul:]},
  Abstract                 = {Bound states of electron-hole pairs in semiconductors demonstrate a hydrogen-like behavior in their high-lying excited states that are also known as Rydberg exciton states. The strong interaction between excitons in levels with high principal quantum numbers prevents the creation of more than one exciton in a small crystal; resulting in the Rydberg blockade effect. Here, we propose a new kind of solid-state single-photon source based on the recently observed Rydberg blockade effect for excitons in cuprous oxide. Our quantitative estimates based on single and double excitation probability dynamics indicate that GHz rates and values of the second-order correlation function g2 (0) below the percent level can be simultaneously achievable. These results should pave the way to explore applications of Rydberg excitons in photonic quantum information processing.},
  Affiliation              = {Institute for Quantum Science and Technology, Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada},
  Art_number               = {215301},
  Author_keywords          = {Rydberg blockade; Rydberg excitons; single-photon sources},
  Document_type            = {Article},
  Doi                      = {10.1088/1361-6455/aa8d7c},
  Source                   = {Scopus},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85032746181&doi=10.1088%2f1361-6455%2faa8d7c&partnerID=40&md5=6ddff869582040071c05e99ed42b32fd}
}

Bound states of electron-hole pairs in semiconductors demonstrate a hydrogen-like behavior in their high-lying excited states that are also known as Rydberg exciton states. The strong interaction between excitons in levels with high principal quantum numbers prevents the creation of more than one exciton in a small crystal; resulting in the Rydberg blockade effect. Here, we propose a new kind of solid-state single-photon source based on the recently observed Rydberg blockade effect for excitons in cuprous oxide. Our quantitative estimates based on single and double excitation probability dynamics indicate that GHz rates and values of the second-order correlation function g2 (0) below the percent level can be simultaneously achievable. These results should pave the way to explore applications of Rydberg excitons in photonic quantum information processing.

@Article{Kupchak2017,
  Title                    = {Time-bin-to-polarization conversion of ultrafast photonic qubits},
  Author                   = {Kupchak, C. and Bustard, P.J. and Heshami, K. and Erskine, J. and Spanner, M. and England, D.G. and Sussman, B.J.},
  Journal                  = {Physical Review A},
  Year                     = {2017},
  Number                   = {5},
  Volume                   = {96},

  __markedentry            = {[paul:]},
  Abstract                 = {The encoding of quantum information in photonic time-bin qubits is apt for long-distance quantum communication schemes. In practice, due to technical constraints such as detector response time, or the speed with which copolarized time-bins can be switched, other encodings, e.g., polarization, are often preferred for operations like state detection. Here, we present the conversion of qubits between polarization and time-bin encodings by using a method that is based on an ultrafast optical Kerr shutter and attain efficiencies of 97% and an average fidelity of 0.827$\pm$0.003 with shutter speeds near 1 ps. Our demonstration delineates an essential requirement for the development of hybrid and high-rate optical quantum networks. {\copyright} 2017 American Physical Society.},
  Affiliation              = {Department of Physics, University of Ottawa, Ottawa, ON, Canada; National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada},
  Art_number               = {053812},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.96.053812},
  Source                   = {Scopus},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85033582063&doi=10.1103%2fPhysRevA.96.053812&partnerID=40&md5=befc876df8ad61786431df849d8f9cbf}
}

The encoding of quantum information in photonic time-bin qubits is apt for long-distance quantum communication schemes. In practice, due to technical constraints such as detector response time, or the speed with which copolarized time-bins can be switched, other encodings, e.g., polarization, are often preferred for operations like state detection. Here, we present the conversion of qubits between polarization and time-bin encodings by using a method that is based on an ultrafast optical Kerr shutter and attain efficiencies of 97% and an average fidelity of 0.827$±$0.003 with shutter speeds near 1 ps. Our demonstration delineates an essential requirement for the development of hybrid and high-rate optical quantum networks. © 2017 American Physical Society.

@Article{Marceau2017,
  Title                    = {{Molecular Frame Reconstruction Using Time-Domain Photoionization Interferometry}},
  Author                   = {Marceau, Claude and Makhija, Varun and Platzer, Dominique and Naumov, A. Yu. and Corkum, P. B. and Stolow, Albert and Villeneuve, D. M. and Hockett, Paul},
  Journal                  = {Physical Review Letters},
  Year                     = {2017},

  Month                    = aug,
  Number                   = {8},
  Pages                    = {083401},
  Volume                   = {119},

  __markedentry            = {[paul:]},
  Archiveprefix            = {arXiv},
  Arxivid                  = {1701.08432},
  Doi                      = {10.1103/PhysRevLett.119.083401},
  Eprint                   = {1701.08432},
  ISSN                     = {0031-9007},
  Publisher                = {American Physical Society},
  Timestamp                = {2018.07.12}
}

@Article{Sit2017,
  Title                    = {High-dimensional intracity quantum cryptography with structured photons},
  Author                   = {Sit, A. and Bouchard, F. and Fickler, R. and Gagnon-Bischoff, J. and Larocque, H. and Heshami, K. and Elser, D. and Peuntinger, C. and G{\"{u}}nthner, K. and Heim, B. and Marquardt, C. and Leuchs, G. and Boyd, R.W. and Karimi, E.},
  Journal                  = {Optica},
  Year                     = {2017},
  Number                   = {9},
  Pages                    = {1006--1010},
  Volume                   = {4},

  __markedentry            = {[paul:]},
  Abstract                 = {Quantum key distribution (QKD) promises information-theoretically secure communication and is already on the verge of commercialization. The next step will be to implement high-dimensional protocols in order to improve noise resistance and increase the data rate. Hitherto, no experimental verification of high-dimensional QKD in the single-photon regime has been conducted outside of the laboratory. Here, we report the realization of such a single-photon QKD system in a turbulent free-space link of 0.3 km over the city of Ottawa, taking advantage of both the spin and orbital angular momentum photonic degrees of freedom. This combination of optical angular momenta allows us to create a 4-dimensional quantum state; wherein, using a high-dimensional BB84 protocol, a quantum bit error rate of 11% was attained with a corresponding secret key rate of 0.65 bits per sifted photon. In comparison, an error rate of 5% with a secret key rate of 0.43 bits per sifted photon is achieved for the case of 2-dimensional structured photons. We thus demonstrate that, even through moderate turbulence without active wavefront correction, high-dimensional photon states are advantageous for securely transmitting more information. This opens the way for intracity high-dimensional quantum communications under realistic conditions. {\copyright} 2017 Optical Society of America.},
  Affiliation              = {Physics Department, Centre for Research in Photonics, University of Ottawa, Advanced Research Complex, 25 Templeton, Ottawa, ON, Canada; National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada; Max-Planck-Institut f�r die Physik des Lichts, Staudtstra�e 2, Erlangen, Germany; Institut f�r Opti, Information und Photonik, Universit�t Erlangen-N�rnberg, Staudtstra�e 7/B2, Erlangen, Germany; Institute of Optics, University of Rochester, Rochester, NY, United States; Department of Physics, Institute for Advanced Studies in Basic Sciences, Zanjan, Iran},
  Author_keywords          = {Free-space optical communication; Optical vortices; Quantum cryptography},
  Document_type            = {Article},
  Doi                      = {10.1364/OPTICA.4.001006},
  Source                   = {Scopus},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029861458&doi=10.1364%2fOPTICA.4.001006&partnerID=40&md5=cc2fd01a976a7229c3f7ee2f141b021c}
}

Quantum key distribution (QKD) promises information-theoretically secure communication and is already on the verge of commercialization. The next step will be to implement high-dimensional protocols in order to improve noise resistance and increase the data rate. Hitherto, no experimental verification of high-dimensional QKD in the single-photon regime has been conducted outside of the laboratory. Here, we report the realization of such a single-photon QKD system in a turbulent free-space link of 0.3 km over the city of Ottawa, taking advantage of both the spin and orbital angular momentum photonic degrees of freedom. This combination of optical angular momenta allows us to create a 4-dimensional quantum state; wherein, using a high-dimensional BB84 protocol, a quantum bit error rate of 11% was attained with a corresponding secret key rate of 0.65 bits per sifted photon. In comparison, an error rate of 5% with a secret key rate of 0.43 bits per sifted photon is achieved for the case of 2-dimensional structured photons. We thus demonstrate that, even through moderate turbulence without active wavefront correction, high-dimensional photon states are advantageous for securely transmitting more information. This opens the way for intracity high-dimensional quantum communications under realistic conditions. © 2017 Optical Society of America.

@Article{Villeneuve2017,
  Title                    = {{Coherent imaging of an attosecond electron wave packet}},
  Author                   = {Villeneuve, D M and Hockett, Paul and Vrakking, M J J and Niikura, Hiromichi},
  Journal                  = {Science},
  Year                     = {2017},

  Month                    = jun,
  Number                   = {6343},
  Pages                    = {1150--1153},
  Volume                   = {356},

  __markedentry            = {[paul:]},
  Abstract                 = {Electrons detached from atoms or molecules by photoionization carry information about the quantum state from which they originate, as well as the continuum states into which they are released. Generally, the photoelectron momentum distribution is composed of a coherent sum of angular momentum components, each with an amplitude and phase. Here we show, by using photoionization of neon, that a train of attosecond pulses synchronized with an infrared laser field can be used to disentangle these angular momentum components. Two-color, two-photon ionization via a Stark-shifted intermediate state creates an almost pure f-wave with a magnetic quantum number of zero. Interference of the f-wave with a spherically symmetric s-wave provides a holographic reference that enables phase-resolved imaging of the f-wave. I n the Copenhagen interpretation of quantum mechanics, a particle is fully described by its complex wave function Y, which is charac-terized by both an amplitude and phase. How-ever, only the square modulus of the wave function, |Y| 2 , can be directly observed (1, 2). Re-cent developments in attosecond technology based on electron-ion recollision (3) have pro-vided experimental tools for the imaging of the electronic wave function (not its square) in bound states or ionization continua. High-harmonic spec-troscopy on aligned molecules was used to re-construct the highest-occupied molecular orbital of nitrogen (4, 5) and to observe charge migra-tion (6). Strong-field tunneling was used to mea-sure the square modulus of the highest-occupied molecular orbital for selected molecules (7). Fur-thermore, recollision holography (8, 9) permitted a measurement of the phase and amplitude of a continuum electron generated in an intense laser field. Complementary to recollision-based measure-ments, photoelectron spectroscopy with atto-second extreme ultraviolet (XUV) pulses has also measured photoelectron wave packets in continuum states (10--16) by exploiting quantum interferences (17--19). However, decomposition of the wave function of an ejected photoelec-tron into angular momentum eigenstates with a fully characterized amplitude and phase is more difficult. First, in general, a one-photon transition with linearly polarized light gener-ates two orbital angular momentum (') states, according to the selection rule D ' $\sfrac{1}{4}$ T1. Second, because the initial state has a {\dh}2' {\th} 1{\TH}-fold de-generacy (labeled by m, the magnetic quan-tum number) and because m is conserved for interactions with linearly polarized light, photo-electron waves with a range of m are produced. Hence, the photoelectron momentum distribution contains a sum of contributions from different initial states, each of which is a coherent sum of different angular momentum components, making it difficult to decompose the continuum state into individual angular momentum com-ponents (20--22). Here we preferentially create an almost pure f-wave continuum wave function with m = 0 in neon by using an attosecond XUV pulse train synchronized with an infrared (IR) laser pulse through the process of high-harmonic genera-tion. The isolation of the f-wave with m = 0 is attributed to the XUV excitation to a resonant bound state that is Stark-shifted by the IR field.},
  Doi                      = {10.1126/science.aam8393},
  ISSN                     = {0036-8075},
  Timestamp                = {2018.07.12}
}

Electrons detached from atoms or molecules by photoionization carry information about the quantum state from which they originate, as well as the continuum states into which they are released. Generally, the photoelectron momentum distribution is composed of a coherent sum of angular momentum components, each with an amplitude and phase. Here we show, by using photoionization of neon, that a train of attosecond pulses synchronized with an infrared laser field can be used to disentangle these angular momentum components. Two-color, two-photon ionization via a Stark-shifted intermediate state creates an almost pure f-wave with a magnetic quantum number of zero. Interference of the f-wave with a spherically symmetric s-wave provides a holographic reference that enables phase-resolved imaging of the f-wave. I n the Copenhagen interpretation of quantum mechanics, a particle is fully described by its complex wave function Y, which is charac-terized by both an amplitude and phase. How-ever, only the square modulus of the wave function, |Y| 2 , can be directly observed (1, 2). Re-cent developments in attosecond technology based on electron-ion recollision (3) have pro-vided experimental tools for the imaging of the electronic wave function (not its square) in bound states or ionization continua. High-harmonic spec-troscopy on aligned molecules was used to re-construct the highest-occupied molecular orbital of nitrogen (4, 5) and to observe charge migra-tion (6). Strong-field tunneling was used to mea-sure the square modulus of the highest-occupied molecular orbital for selected molecules (7). Fur-thermore, recollision holography (8, 9) permitted a measurement of the phase and amplitude of a continuum electron generated in an intense laser field. Complementary to recollision-based measure-ments, photoelectron spectroscopy with atto-second extreme ultraviolet (XUV) pulses has also measured photoelectron wave packets in continuum states (10–16) by exploiting quantum interferences (17–19). However, decomposition of the wave function of an ejected photoelec-tron into angular momentum eigenstates with a fully characterized amplitude and phase is more difficult. First, in general, a one-photon transition with linearly polarized light gener-ates two orbital angular momentum (') states, according to the selection rule D ' $\sfrac{1}{4}$ T1. Second, because the initial state has a ð2' þ 1Þ-fold de-generacy (labeled by m, the magnetic quan-tum number) and because m is conserved for interactions with linearly polarized light, photo-electron waves with a range of m are produced. Hence, the photoelectron momentum distribution contains a sum of contributions from different initial states, each of which is a coherent sum of different angular momentum components, making it difficult to decompose the continuum state into individual angular momentum com-ponents (20–22). Here we preferentially create an almost pure f-wave continuum wave function with m = 0 in neon by using an attosecond XUV pulse train synchronized with an infrared (IR) laser pulse through the process of high-harmonic genera-tion. The isolation of the f-wave with m = 0 is attributed to the XUV excitation to a resonant bound state that is Stark-shifted by the IR field.

@Article{Wang2017,
  Title                    = {Monitoring non-adiabatic dynamics in CS2 with time- and energy-resolved photoelectron spectra of wavepackets},
  Author                   = {Wang, K. and McKoy, V. and Hockett, P. and Stolow, A. and Schuurman, M.S.},
  Journal                  = {Chemical Physics Letters},
  Year                     = {2017},

  Abstract                 = {We report results from a novel fully ab initio method for simulating the time-resolved photoelectron angular distributions around conical intersections in CS2. The technique employs wavepacket densities obtained with the multiple spawning method in conjunction with geometry- and energy-dependent photoionization matrix elements. The robust agreement of the calculated molecular-frame photoelectron angular distributions with measured values for CS2 demonstrates that this approach can successfully illuminate, and disentangle, the underlying coupled nuclear and electronic dynamics around conical intersections in polyatomic molecules. © 2017 Elsevier B.V.},
  Document_type            = {Article in Press},
  Doi                      = {10.1016/j.cplett.2017.02.014},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85013194897&doi=10.1016%2fj.cplett.2017.02.014&partnerID=40&md5=76b56f8a2c14354ae018554315eccbd6}
}

We report results from a novel fully ab initio method for simulating the time-resolved photoelectron angular distributions around conical intersections in CS2. The technique employs wavepacket densities obtained with the multiple spawning method in conjunction with geometry- and energy-dependent photoionization matrix elements. The robust agreement of the calculated molecular-frame photoelectron angular distributions with measured values for CS2 demonstrates that this approach can successfully illuminate, and disentangle, the underlying coupled nuclear and electronic dynamics around conical intersections in polyatomic molecules. © 2017 Elsevier B.V.

@Article{Zarkeshian2017,
  Title                    = {Entanglement between more than two hundred macroscopic atomic ensembles in a solid},
  Author                   = {Zarkeshian, P. and Deshmukh, C. and Sinclair, N. and Goyal, S.K. and Aguilar, G.H. and Lefebvre, P. and Puigibert, M.G. and Verma, V.B. and Marsili, F. and Shaw, M.D. and Nam, S.W. and Heshami, K. and Oblak, D. and Tittel, W. and Simon, C.},
  Journal                  = {Nature Communications},
  Year                     = {2017},
  Number                   = {1},
  Volume                   = {8},

  __markedentry            = {[paul:]},
  Abstract                 = {There are both fundamental and practical motivations for studying whether quantum entanglement can exist in macroscopic systems. However, multiparty entanglement is generally fragile and difficult to quantify. Dicke states are multiparty entangled states where a single excitation is delocalized over many systems. Building on previous work on quantum memories for photons, we create a Dicke state in a solid by storing a single photon in a crystal that contains many large atomic ensembles with distinct resonance frequencies. The photon is re-emitted at a well-defined time due to an interference effect analogous to multi-slit diffraction. We derive a lower bound for the number of entangled ensembles based on the contrast of the interference and the single-photon character of the input, and we experimentally demonstrate entanglement between over two hundred ensembles, each containing a billion atoms. We also illustrate the fact that each individual ensemble contains further entanglement. {\copyright} 2017 The Author(s).},
  Affiliation              = {Institute for Quantum Science and Technology, Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, AB, Canada; National Institute of Standards and Technology, Boulder, CO, United States; Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA, United States; National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada},
  Art_number               = {906},
  Document_type            = {Article},
  Doi                      = {10.1038/s41467-017-00897-7},
  Source                   = {Scopus},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85031702516&doi=10.1038%2fs41467-017-00897-7&partnerID=40&md5=908ab4fd49c99d99065af18814fdb9b6}
}

There are both fundamental and practical motivations for studying whether quantum entanglement can exist in macroscopic systems. However, multiparty entanglement is generally fragile and difficult to quantify. Dicke states are multiparty entangled states where a single excitation is delocalized over many systems. Building on previous work on quantum memories for photons, we create a Dicke state in a solid by storing a single photon in a crystal that contains many large atomic ensembles with distinct resonance frequencies. The photon is re-emitted at a well-defined time due to an interference effect analogous to multi-slit diffraction. We derive a lower bound for the number of entangled ensembles based on the contrast of the interference and the single-photon character of the input, and we experimentally demonstrate entanglement between over two hundred ensembles, each containing a billion atoms. We also illustrate the fact that each individual ensemble contains further entanglement. © 2017 The Author(s).

@Article{Bustard2016,
  Title                    = {Reducing noise in a Raman quantum memory},
  Author                   = {Bustard, P.J. and England, D.G. and Heshami, K. and Kupchak, C. and Sussman, B.J.},
  Journal                  = {Optics Letters},
  Year                     = {2016},
  Number                   = {21},
  Pages                    = {5055-5058},
  Volume                   = {41},
  Abstract                 = {Optical quantum memories are an important component of future optical and hybrid quantum technologies. Raman schemes are strong candidates for use with ultrashort optical pulses due to their broad bandwidth; however, the elimination of deleterious four-wave mixing noise from Raman memories is critical for practical applications. Here, we demonstrate a quantum memory using the rotational states of hydrogen molecules at room temperature. Polarization selection rules prohibit four-wave mixing, allowing the storage and retrieval of attenuated coherent states with a mean photon number 0.9 and a pulse duration 175 fs. The 1/e memory lifetime is 85.5 ps, demonstrating a time-bandwidth product of ≈480 in a memory that is well suited for use with broadband heralded down-conversion and fiber-based photon sources. © 2016 Optical Society of America.},
  Document_type            = {Article},
  Doi                      = {10.1364/OL.41.005055},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84995468087&doi=10.1364%2fOL.41.005055&partnerID=40&md5=8c2415100d2621542196e984ff35a4ec}
}

Optical quantum memories are an important component of future optical and hybrid quantum technologies. Raman schemes are strong candidates for use with ultrashort optical pulses due to their broad bandwidth; however, the elimination of deleterious four-wave mixing noise from Raman memories is critical for practical applications. Here, we demonstrate a quantum memory using the rotational states of hydrogen molecules at room temperature. Polarization selection rules prohibit four-wave mixing, allowing the storage and retrieval of attenuated coherent states with a mean photon number 0.9 and a pulse duration 175 fs. The 1/e memory lifetime is 85.5 ps, demonstrating a time-bandwidth product of ≈480 in a memory that is well suited for use with broadband heralded down-conversion and fiber-based photon sources. © 2016 Optical Society of America.

@Article{Bustard2016a,
  Title                    = {Raman-induced slow-light delay of THz-bandwidth pulses},
  Author                   = {Bustard, P.J. and Heshami, K. and England, D.G. and Spanner, M. and Sussman, B.J.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2016},
  Number                   = {4},
  Volume                   = {93},
  Abstract                 = {We propose and experimentally demonstrate a scheme to generate optically controlled delays based on off-resonant Raman absorption. Dispersion in a transparency window between two neighboring, optically activated Raman absorption lines is used to reduce the group velocity of broadband 765 nm pulses. We implement this approach in a potassium titanyl phosphate (KTP) waveguide at room temperature, and demonstrate Raman-induced delays of up to 140 fs for a 650-fs duration, 1.8-THz bandwidth, pulse. Our approach should be applicable to single-photon signals, offers wavelength tunability, and is a step toward processing ultrafast photons. © 2016 American Physical Society.},
  Art_number               = {043810},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.93.043810},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84963657422&doi=10.1103%2fPhysRevA.93.043810&partnerID=40&md5=26332fb545ba4a09044c24be35daf8fc}
}

We propose and experimentally demonstrate a scheme to generate optically controlled delays based on off-resonant Raman absorption. Dispersion in a transparency window between two neighboring, optically activated Raman absorption lines is used to reduce the group velocity of broadband 765 nm pulses. We implement this approach in a potassium titanyl phosphate (KTP) waveguide at room temperature, and demonstrate Raman-induced delays of up to 140 fs for a 650-fs duration, 1.8-THz bandwidth, pulse. Our approach should be applicable to single-photon signals, offers wavelength tunability, and is a step toward processing ultrafast photons. © 2016 American Physical Society.

@Conference{England2016a,
  Title                    = {Applications of a picosecond-lifetime quantum memory},
  Author                   = {England, D.G. and Bustard, P.J. and Sussman, B.J. and Fisher, K.A.G. and Maclean, J.-P.W. and Resch, K.J.},
  Year                     = {2016},
  Abstract                 = {We demonstrate a quantum memory using the optical phonon modes of room-temperature diamond [1, 2]. The memory stores THz-bandwidth single photons produced by parametric down-conversion for several picoseconds and offers operations upon the stored light. © 2016 OSA.},
  Art_number               = {7787652},
  Document_type            = {Conference Paper},
  Journal                  = {2016 Conference on Lasers and Electro-Optics, CLEO 2016},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85010638292&partnerID=40&md5=b253d98cf0057a473c074b81c9359f6e}
}

We demonstrate a quantum memory using the optical phonon modes of room-temperature diamond [1, 2]. The memory stores THz-bandwidth single photons produced by parametric down-conversion for several picoseconds and offers operations upon the stored light. © 2016 OSA.

@Article{England2016,
  Title                    = {Phonon-Mediated Nonclassical Interference in Diamond},
  Author                   = {England, D.G. and Fisher, K.A.G. and MacLean, J.-P.W. and Bustard, P.J. and Heshami, K. and Resch, K.J. and Sussman, B.J.},
  Journal                  = {Physical Review Letters},
  Year                     = {2016},
  Number                   = {7},
  Volume                   = {117},
  Abstract                 = {Quantum interference of single photons is a fundamental aspect of many photonic quantum processing and communication protocols. Interference requires that the multiple pathways through an interferometer be temporally indistinguishable to within the coherence time of the photon. In this Letter, we use a diamond quantum memory to demonstrate interference between quantum pathways, initially temporally separated by many multiples of the optical coherence time. The quantum memory can be viewed as a light-matter beam splitter, mapping a THz-bandwidth single photon to a variable superposition of the output optical mode and stored phononic mode. Because the memory acts both as a beam splitter and as a buffer, the relevant coherence time for interference is not that of the photon, but rather that of the memory. We use this mechanism to demonstrate nonclassical single-photon and two-photon interference between quantum pathways initially separated by several picoseconds, even though the duration of the photons themselves is just ∼250 fs. © 2016 American Physical Society.},
  Art_number               = {073603},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.117.073603},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84982095459&doi=10.1103%2fPhysRevLett.117.073603&partnerID=40&md5=25216c896531ed3faf23fb7fbcaaf41c}
}

Quantum interference of single photons is a fundamental aspect of many photonic quantum processing and communication protocols. Interference requires that the multiple pathways through an interferometer be temporally indistinguishable to within the coherence time of the photon. In this Letter, we use a diamond quantum memory to demonstrate interference between quantum pathways, initially temporally separated by many multiples of the optical coherence time. The quantum memory can be viewed as a light-matter beam splitter, mapping a THz-bandwidth single photon to a variable superposition of the output optical mode and stored phononic mode. Because the memory acts both as a beam splitter and as a buffer, the relevant coherence time for interference is not that of the photon, but rather that of the memory. We use this mechanism to demonstrate nonclassical single-photon and two-photon interference between quantum pathways initially separated by several picoseconds, even though the duration of the photons themselves is just ∼250 fs. © 2016 American Physical Society.

@Article{Fisher2016,
  Title                    = {Frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory},
  Author                   = {Fisher, K.A.G. and England, D.G. and MacLean, J.-P.W. and Bustard, P.J. and Resch, K.J. and Sussman, B.J.},
  Journal                  = {Nature Communications},
  Year                     = {2016},
  Volume                   = {7},
  Abstract                 = {The spectral manipulation of photons is essential for linking components in a quantum network. Large frequency shifts are needed for conversion between optical and telecommunication frequencies, while smaller shifts are useful for frequency-multiplexing quantum systems, in the same way that wavelength division multiplexing is used in classical communications. Here we demonstrate frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory. Heralded 723.5 nm photons, with 4.1 nm bandwidth, are stored as optical phonons in the diamond via a Raman transition. Upon retrieval from the diamond memory, the spectral shape of the photons is determined by a tunable read pulse through the reverse Raman transition. We report central frequency tunability over 4.2 times the input bandwidth, and bandwidth modulation between 0.5 and 1.9 times the input bandwidth. Our results demonstrate the potential for diamond, and Raman memories in general, as an integrated platform for photon storage and spectral conversion.},
  Art_number               = {11200},
  Document_type            = {Article},
  Doi                      = {10.1038/ncomms11200},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962682888&doi=10.1038%2fncomms11200&partnerID=40&md5=f93fc97191350eaedccdc73f77a90d27}
}

The spectral manipulation of photons is essential for linking components in a quantum network. Large frequency shifts are needed for conversion between optical and telecommunication frequencies, while smaller shifts are useful for frequency-multiplexing quantum systems, in the same way that wavelength division multiplexing is used in classical communications. Here we demonstrate frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory. Heralded 723.5 nm photons, with 4.1 nm bandwidth, are stored as optical phonons in the diamond via a Raman transition. Upon retrieval from the diamond memory, the spectral shape of the photons is determined by a tunable read pulse through the reverse Raman transition. We report central frequency tunability over 4.2 times the input bandwidth, and bandwidth modulation between 0.5 and 1.9 times the input bandwidth. Our results demonstrate the potential for diamond, and Raman memories in general, as an integrated platform for photon storage and spectral conversion.

@Article{Heshami2016,
  Title                    = {Quantum memories: emerging applications and recent advances},
  Author                   = {Heshami, K. and England, D.G. and Humphreys, P.C. and Bustard, P.J. and Acosta, V.M. and Nunn, J. and Sussman, B.J.},
  Journal                  = {Journal of Modern Optics},
  Year                     = {2016},
  Number                   = {20},
  Pages                    = {2005-2028},
  Volume                   = {63},
  Abstract                 = {Quantum light–matter interfaces are at the heart of photonic quantum technologies. Quantum memories for photons, where non-classical states of photons are mapped onto stationary matter states and preserved for subsequent retrieval, are technical realizations enabled by exquisite control over interactions between light and matter. The ability of quantum memories to synchronize probabilistic events makes them a key component in quantum repeaters and quantum computation based on linear optics. This critical feature has motivated many groups to dedicate theoretical and experimental research to develop quantum memory devices. In recent years, exciting new applications, and more advanced developments of quantum memories, have proliferated. In this review, we outline some of the emerging applications of quantum memories in optical signal processing, quantum computation and non-linear optics. We review recent experimental and theoretical developments, and their impacts on more advanced photonic quantum technologies based on quantum memories. © 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.},
  Document_type            = {Review},
  Doi                      = {10.1080/09500340.2016.1148212},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84961215936&doi=10.1080%2f09500340.2016.1148212&partnerID=40&md5=c31cd86dff39a0b63548b7da7f4d8cfa}
}

Quantum light–matter interfaces are at the heart of photonic quantum technologies. Quantum memories for photons, where non-classical states of photons are mapped onto stationary matter states and preserved for subsequent retrieval, are technical realizations enabled by exquisite control over interactions between light and matter. The ability of quantum memories to synchronize probabilistic events makes them a key component in quantum repeaters and quantum computation based on linear optics. This critical feature has motivated many groups to dedicate theoretical and experimental research to develop quantum memory devices. In recent years, exciting new applications, and more advanced developments of quantum memories, have proliferated. In this review, we outline some of the emerging applications of quantum memories in optical signal processing, quantum computation and non-linear optics. We review recent experimental and theoretical developments, and their impacts on more advanced photonic quantum technologies based on quantum memories. © 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

@Article{Hockett2016b,
  Title                    = {{ePSproc: Post-processing suite for ePolyScat electron-molecule scattering calculations}},
  Author                   = {Hockett, Paul},
  Journal                  = {Authorea},
  Year                     = {2016},

  __markedentry            = {[paul:]},
  Doi                      = {10.6084/m9.figshare.3545639},
  Timestamp                = {2018.07.12},
  Url                      = {https://www.authorea.com/users/71114/articles/122402/{\_}show{\_}article}
}

@Article{Hockett2016c,
  Title                    = {{Response to 'Comment on "Time delays in molecular photoionization"': Extended Discussion {\&} Technical Notes}},
  Author                   = {Hockett, Paul and Frumker, Eugene},
  Journal                  = {arXiv},
  Year                     = {2016},

  Month                    = dec,
  Volume                   = {1612.00481},

  __markedentry            = {[paul:]},
  Abstract                 = {In a comment on our article Time delays in molecular photoionization [1], Baykusheva {\&} W$\backslash$"orner reproduce canonical scattering theory, and assert that our results are inconsistent with this well-established theory [2]. We absolutely refute this assertion and the spirit of the comment, although we do agree with Baykusheva {\&} W$\backslash$"orner that the textbook theory is correct. In a short response, Response to Comment on "Time delays in molecular photoionization" [3], we have already provided a clear rebuttal of the comment, but gave no technical details. In this fuller response we extend those brief comments in the spirit of completeness and clarity, and provide three clear rebuttals to Baykusheva {\&} W$\backslash$"orner based on (1) logical fallacy (category error), (2) theoretical details of the original article, (3) textural content of the original article. In particular, rebuttal (1) clearly and trivially points to the fact that there is no issue here whatsoever, with recourse to theoretical details barely required to demonstrate this, as outlined in the short version of our response. Our numerical results are correct and reproduce known physical phenomena, as discussed in the original article hence, as careful readers will recognise, the formalism used is canonical scattering theory, and cannot be anything other. In fact, there is no new fundamental physics here to dispute whatsoever, and nor was this the raison d'etre of the original article. Additionally, rebuttal (2) provides the opportunity to discuss, at length, some of these textbook aspects of photoionization theory, and we hope this discussion might be of service to new researchers entering this challenging field.},
  Archiveprefix            = {arXiv},
  Arxivid                  = {1612.00481},
  Eprint                   = {1612.00481},
  Timestamp                = {2018.07.12},
  Url                      = {http://arxiv.org/abs/1612.00481}
}

In a comment on our article Time delays in molecular photoionization [1], Baykusheva & W$\$"orner reproduce canonical scattering theory, and assert that our results are inconsistent with this well-established theory [2]. We absolutely refute this assertion and the spirit of the comment, although we do agree with Baykusheva & W$\$"orner that the textbook theory is correct. In a short response, Response to Comment on "Time delays in molecular photoionization" [3], we have already provided a clear rebuttal of the comment, but gave no technical details. In this fuller response we extend those brief comments in the spirit of completeness and clarity, and provide three clear rebuttals to Baykusheva & W$\$"orner based on (1) logical fallacy (category error), (2) theoretical details of the original article, (3) textural content of the original article. In particular, rebuttal (1) clearly and trivially points to the fact that there is no issue here whatsoever, with recourse to theoretical details barely required to demonstrate this, as outlined in the short version of our response. Our numerical results are correct and reproduce known physical phenomena, as discussed in the original article hence, as careful readers will recognise, the formalism used is canonical scattering theory, and cannot be anything other. In fact, there is no new fundamental physics here to dispute whatsoever, and nor was this the raison d'etre of the original article. Additionally, rebuttal (2) provides the opportunity to discuss, at length, some of these textbook aspects of photoionization theory, and we hope this discussion might be of service to new researchers entering this challenging field.

@Article{Hockett2016,
  Title                    = {Time delay in molecular photoionization},
  Author                   = {Hockett, P. and Frumker, E. and Villeneuve, D.M. and Corkum, P.B.},
  Journal                  = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  Year                     = {2016},
  Number                   = {9},
  Volume                   = {49},

  Abstract                 = {Time-delays in the photoionization of molecules are investigated. As compared to atomic ionization, the time-delays expected from molecular ionization present a much richer phenomenon, with a strong spatial dependence due to the anisotropic nature of the molecular scattering potential. We investigate this from a scattering theory perspective, and make use of molecular photoionization calculations to examine this effect in representative homonuclear and hetronuclear diatomic molecules, nitrogen and carbon monoxide. We present energy and angle-resolved maps of the Wigner delay time for single-photon valence ionization, and discuss the possibilities for experimental measurements. © 2016 IOP Publishing Ltd.},
  Art_number               = {095602},
  Document_type            = {Article},
  Doi                      = {10.1088/0953-4075/49/9/095602},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84965050711&doi=10.1088%2f0953-4075%2f49%2f9%2f095602&partnerID=40&md5=d819dc5998c7320934a432c0f35df971}
}

Time-delays in the photoionization of molecules are investigated. As compared to atomic ionization, the time-delays expected from molecular ionization present a much richer phenomenon, with a strong spatial dependence due to the anisotropic nature of the molecular scattering potential. We investigate this from a scattering theory perspective, and make use of molecular photoionization calculations to examine this effect in representative homonuclear and hetronuclear diatomic molecules, nitrogen and carbon monoxide. We present energy and angle-resolved maps of the Wigner delay time for single-photon valence ionization, and discuss the possibilities for experimental measurements. © 2016 IOP Publishing Ltd.

@Article{Hockett2016a,
  Title                    = {{Augmented Reality with Hololens: Experiential Architectures Embedded in the Real World}},
  Author                   = {Hockett, Paul and Ingleby, Tim},
  Journal                  = {arXiv},
  Year                     = {2016},

  Month                    = oct,
  Pages                    = {1--10},

  __markedentry            = {[paul:]},
  Abstract                 = {Early hands-on experiences with the Microsoft Hololens augmented/mixed reality device are reported and discussed, with a general aim of exploring basic 3D visualization. A range of usage cases are tested, including data visualization and immersive data spaces, in-situ visualization of 3D models and full scale architectural form visualization. Ultimately, the Hololens is found to provide a remarkable tool for moving from traditional visualization of 3D objects on a 2D screen, to fully experiential 3D visualizations embedded in the real world.},
  Archiveprefix            = {arXiv},
  Arxivid                  = {1610.04281},
  Doi                      = {10.22541/au.148821660.05483993},
  Eprint                   = {1610.04281},
  Timestamp                = {2018.07.12},
  Url                      = {http://arxiv.org/abs/1610.04281}
}

Early hands-on experiences with the Microsoft Hololens augmented/mixed reality device are reported and discussed, with a general aim of exploring basic 3D visualization. A range of usage cases are tested, including data visualization and immersive data spaces, in-situ visualization of 3D models and full scale architectural form visualization. Ultimately, the Hololens is found to provide a remarkable tool for moving from traditional visualization of 3D objects on a 2D screen, to fully experiential 3D visualizations embedded in the real world.

@Article{Sinclair2016,
  Title                    = {Proposal and proof-of-principle demonstration of non-destructive detection of photonic qubits using a Tm:LiNbO3 waveguide},
  Author                   = {Sinclair, N. and Heshami, K. and Deshmukh, C. and Oblak, D. and Simon, C. and Tittel, W.},
  Journal                  = {Nature Communications},
  Year                     = {2016},
  Volume                   = {7},
  Abstract                 = {Non-destructive detection of photonic qubits is an enabling technology for quantum information processing and quantum communication. For practical applications, such as quantum repeaters and networks, it is desirable to implement such detection in a way that allows some form of multiplexing as well as easy integration with other components such as solid-state quantum memories. Here, we propose an approach to non-destructive photonic qubit detection that promises to have all the mentioned features. Mediated by an impurity-doped crystal, a signal photon in an arbitrary time-bin qubit state modulates the phase of an intense probe pulse that is stored during the interaction. Using a thulium-doped waveguide in LiNbO 3, we perform a proof-of-principle experiment with macroscopic signal pulses, demonstrating the expected cross-phase modulation as well as the ability to preserve the coherence between temporal modes. Our findings open the path to a new key component of quantum photonics based on rare-earth-ion-doped crystals. © 2016 The Author(s).},
  Art_number               = {13454},
  Document_type            = {Article},
  Doi                      = {10.1038/ncomms13454},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84995695227&doi=10.1038%2fncomms13454&partnerID=40&md5=e705ed00c91b2eccf16ade12ee34f977}
}

Non-destructive detection of photonic qubits is an enabling technology for quantum information processing and quantum communication. For practical applications, such as quantum repeaters and networks, it is desirable to implement such detection in a way that allows some form of multiplexing as well as easy integration with other components such as solid-state quantum memories. Here, we propose an approach to non-destructive photonic qubit detection that promises to have all the mentioned features. Mediated by an impurity-doped crystal, a signal photon in an arbitrary time-bin qubit state modulates the phase of an intense probe pulse that is stored during the interaction. Using a thulium-doped waveguide in LiNbO 3, we perform a proof-of-principle experiment with macroscopic signal pulses, demonstrating the expected cross-phase modulation as well as the ability to preserve the coherence between temporal modes. Our findings open the path to a new key component of quantum photonics based on rare-earth-ion-doped crystals. © 2016 The Author(s).

@Article{Thekkadath2016,
  Title                    = {Optical quantum memory for ultrafast photons using molecular alignment},
  Author                   = {Thekkadath, G.S. and Heshami, K. and England, D.G. and Bustard, P.J. and Sussman, B.J. and Spanner, M.},
  Journal                  = {Journal of Modern Optics},
  Year                     = {2016},
  Number                   = {20},
  Pages                    = {2093-2100},
  Volume                   = {63},
  Abstract                 = {The absorption of broadband photons in atomic ensembles requires either an effective broadening of the atomic transition linewidth, or an off-resonance Raman interaction. Here, we propose a scheme for a quantum memory capable of storing and retrieving ultrafast photons in an ensemble of two-level atoms using a propagation medium with a time–dependent refractive index generated from aligning an ensemble of gas-phase diatomic molecules. The refractive index dynamics generates an effective longitudinal inhomogeneous broadening of the two-level transition. We numerically demonstrate this scheme for storage and retrieval of a weak pulse as short as 50 fs, with a storage time of up to 20 ps. With additional optical control of the molecular alignment dynamics, the storage time can be extended about one nanosecond leading to time–bandwidth products of order 104. This scheme could in principle be achieved using either a hollow-core fibre or a high-pressure gas cell, in a gaseous host medium comprised of diatomic molecules and a two-level atomic vapour at room temperature. © 2016, Copyright of the Crown in Canada 2016 The National Research Council of Canada.},
  Document_type            = {Article},
  Doi                      = {10.1080/09500340.2016.1181218},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84966709063&doi=10.1080%2f09500340.2016.1181218&partnerID=40&md5=50baa5bfbb52d3e5b542ff413e200f05}
}

The absorption of broadband photons in atomic ensembles requires either an effective broadening of the atomic transition linewidth, or an off-resonance Raman interaction. Here, we propose a scheme for a quantum memory capable of storing and retrieving ultrafast photons in an ensemble of two-level atoms using a propagation medium with a time–dependent refractive index generated from aligning an ensemble of gas-phase diatomic molecules. The refractive index dynamics generates an effective longitudinal inhomogeneous broadening of the two-level transition. We numerically demonstrate this scheme for storage and retrieval of a weak pulse as short as 50 fs, with a storage time of up to 20 ps. With additional optical control of the molecular alignment dynamics, the storage time can be extended about one nanosecond leading to time–bandwidth products of order 104. This scheme could in principle be achieved using either a hollow-core fibre or a high-pressure gas cell, in a gaseous host medium comprised of diatomic molecules and a two-level atomic vapour at room temperature. © 2016, Copyright of the Crown in Canada 2016 The National Research Council of Canada.

@Article{Wein2016,
  Title                    = {Efficiency of an enhanced linear optical Bell-state measurement scheme with realistic imperfections},
  Author                   = {Wein, S. and Heshami, K. and Fuchs, C.A. and Krovi, H. and Dutton, Z. and Tittel, W. and Simon, C.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2016},
  Number                   = {3},
  Volume                   = {94},
  Abstract                 = {We compare the standard 50%-efficient single beam splitter method for Bell-state measurement to a proposed 75%-efficient auxiliary-photon-enhanced scheme [W. P. Grice, Phys. Rev. A 84, 042331 (2011)PLRAAN1050-294710.1103/PhysRevA.84.042331] in light of realistic conditions. The two schemes are compared with consideration for high input state photon loss, auxiliary state photon loss, detector inefficiency and coupling loss, detector dark counts, and non-number-resolving detectors. We also analyze the two schemes when multiplexed arrays of non-number-resolving detectors are used. Furthermore, we explore the possibility of utilizing spontaneous parametric down-conversion as the auxiliary photon pair source required by the enhanced scheme. In these different cases, we determine the bounds on the detector parameters at which the enhanced scheme becomes superior to the standard scheme and describe the impact of the different imperfections on measurement success rate and discrimination fidelity. This is done using a combination of numeric and analytic techniques. For many of the cases discussed, the size of the Hilbert space and the number of measurement outcomes can be very large, which makes direct numerical solutions computationally costly. To alleviate this problem, all of our numerical computations are performed using pure states. This requires tracking the loss modes until measurement and treating dark counts as variations on measurement outcomes rather than modifications to the state itself. In addition, we provide approximate analytic expressions that illustrate the effect of different imperfections on the Bell-state analyzer quality. © 2016 American Physical Society.},
  Art_number               = {032332},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.94.032332},
  Source                   = {Scopus},
  Timestamp                = {2017.04.27},
  Url                      = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84991720188&doi=10.1103%2fPhysRevA.94.032332&partnerID=40&md5=facad74743002de22721f28d33802c80}
}

We compare the standard 50%-efficient single beam splitter method for Bell-state measurement to a proposed 75%-efficient auxiliary-photon-enhanced scheme [W. P. Grice, Phys. Rev. A 84, 042331 (2011)PLRAAN1050-294710.1103/PhysRevA.84.042331] in light of realistic conditions. The two schemes are compared with consideration for high input state photon loss, auxiliary state photon loss, detector inefficiency and coupling loss, detector dark counts, and non-number-resolving detectors. We also analyze the two schemes when multiplexed arrays of non-number-resolving detectors are used. Furthermore, we explore the possibility of utilizing spontaneous parametric down-conversion as the auxiliary photon pair source required by the enhanced scheme. In these different cases, we determine the bounds on the detector parameters at which the enhanced scheme becomes superior to the standard scheme and describe the impact of the different imperfections on measurement success rate and discrimination fidelity. This is done using a combination of numeric and analytic techniques. For many of the cases discussed, the size of the Hilbert space and the number of measurement outcomes can be very large, which makes direct numerical solutions computationally costly. To alleviate this problem, all of our numerical computations are performed using pure states. This requires tracking the loss modes until measurement and treating dark counts as variations on measurement outcomes rather than modifications to the state itself. In addition, we provide approximate analytic expressions that illustrate the effect of different imperfections on the Bell-state analyzer quality. © 2016 American Physical Society.

@Article{Boone2015,
  Title                    = {Entanglement over global distances via quantum repeaters with satellite links},
  Author                   = {Boone, K.a , Bourgoin, J.-P.b , Meyer-Scott, E.b , Heshami, K.a c , Jennewein, T.b d , Simon, C.a },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2015},
  Number                   = {5},
  Volume                   = {91},

  Abstract                 = {We study entanglement creation over global distances based on a quantum repeater architecture that uses low-Earth-orbit satellites equipped with entangled photon sources, as well as ground stations equipped with quantum nondemolition detectors and quantum memories. We show that this approach allows entanglement creation at viable rates over distances that are inaccessible via direct transmission through optical fibers or even from very distant satellites. ©2015 American Physical Society.},
  Affiliation              = {Institute for Quantum Science and Technology, Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada; National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada; Quantum Information Science Program, Canadian Institute for Advanced Research, Toronto, ON, Canada},
  Art_number               = {052325},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.91.052325},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84930226291&partnerID=40&md5=5a1a012da102cd9f31b9c45e59247316}
}

We study entanglement creation over global distances based on a quantum repeater architecture that uses low-Earth-orbit satellites equipped with entangled photon sources, as well as ground stations equipped with quantum nondemolition detectors and quantum memories. We show that this approach allows entanglement creation at viable rates over distances that are inaccessible via direct transmission through optical fibers or even from very distant satellites. ©2015 American Physical Society.

@Conference{Bustard2015,
  Title                    = {THz-bandwidth molecular memories for light},
  Author                   = {Bustard, P.J., Erskine, J., England, D.G., Lausten, R., Sussman, B.J.},
  Year                     = {2015},
  Pages                    = {1551p},

  Abstract                 = {We use the vibrational levels of hydrogen molecules as a memory for light to store 100-fs pulses. We also demonstrate non-classical correlations in an emissive quantum memory using rotational levels of hydrogen molecules. © 2014 Optical Society of America.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada},
  Document_type            = {Conference Paper},
  Doi                      = {10.1364/CLEO_QELS.2015.FTh4B.4},
  Journal                  = {CLEO: QELS - Fundamental Science, CLEO_QELS 2015},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84935064598&partnerID=40&md5=d51d599e36619a2283862974c31a3078}
}

We use the vibrational levels of hydrogen molecules as a memory for light to store 100-fs pulses. We also demonstrate non-classical correlations in an emissive quantum memory using rotational levels of hydrogen molecules. © 2014 Optical Society of America.

@Article{England2015,
  Title                    = {Storage and retrieval of THZ-bandwidth single photons using a room-temperature diamond quantum memory},
  Author                   = {England, D.G.a , Fisher, K.A.G.b , Maclean, J.-P.W.b , Bustard, P.J.a , Lausten, R.a , Resch, K.J.b , Sussman, B.J.a },
  Journal                  = {Physical Review Letters},
  Year                     = {2015},
  Number                   = {5},
  Volume                   = {114},

  Abstract                 = {We report the storage and retrieval of single photons, via a quantum memory, in the optical phonons of a room-temperature bulk diamond. The THz-bandwidth heralded photons are generated by spontaneous parametric down-conversion and mapped to phonons via a Raman transition, stored for a variable delay, and released on demand. The second-order correlation of the memory output is g(2)(0)=0.65±0.07, demonstrating a preservation of nonclassical photon statistics throughout storage and retrieval. The memory is low noise, high speed and broadly tunable; it therefore promises to be a versatile light-matter interface for local quantum processing applications. © 2015 American Physical Society.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada; Institute for Quantum Computing, Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON, Canada},
  Art_number               = {053602},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.114.053602},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84922309614&partnerID=40&md5=e5601472921de56d88e2c9fd36aacdb0}
}

We report the storage and retrieval of single photons, via a quantum memory, in the optical phonons of a room-temperature bulk diamond. The THz-bandwidth heralded photons are generated by spontaneous parametric down-conversion and mapped to phonons via a Raman transition, stored for a variable delay, and released on demand. The second-order correlation of the memory output is g(2)(0)=0.65±0.07, demonstrating a preservation of nonclassical photon statistics throughout storage and retrieval. The memory is low noise, high speed and broadly tunable; it therefore promises to be a versatile light-matter interface for local quantum processing applications. © 2015 American Physical Society.

@Conference{Fisher2015,
  Title                    = {Storage and retrieval of ultrafast single photons using a room-temperature diamond quantum memory},
  Author                   = {Fisher, K.A.G.a , England, D.b , Maclean, J.-P.a , Bustard, P.J.b , Lausten, R.b , Resch, K.J.a , Sussman, B.J.b},
  Year                     = {2015},
  Pages                    = {1551p},

  Abstract                 = {We experimentally demonstrated the storage and retrieval of THz-bandwidth single photons in a room-temperature diamond quantum memory. We have shown that the non-classical nature of retrieved light is preserved by the memory process. © 2014 Optical Society of America.},
  Affiliation              = {Institute for Quantum Computing and Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada; National Research Council of Canada, 100 Sussex Drive, Ottawa, Canada},
  Document_type            = {Conference Paper},
  Doi                      = {10.1364/CLEO_QELS.2015.FTh4B.5},
  Journal                  = {CLEO: QELS - Fundamental Science, CLEO_QELS 2015},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84935073646&partnerID=40&md5=745ca7c6b0b95011d2aec8ba6b0c3e77}
}

We experimentally demonstrated the storage and retrieval of THz-bandwidth single photons in a room-temperature diamond quantum memory. We have shown that the non-classical nature of retrieved light is preserved by the memory process. © 2014 Optical Society of America.

@Article{Hockett2015,
  Title                    = {General phenomenology of ionization from aligned molecular ensembles},
  Author                   = {Hockett, P.},
  Journal                  = {New Journal of Physics},
  Year                     = {2015},
  Volume                   = {17},

  Abstract                 = {Single and multi-photon ionization of aligned molecular ensembles is examined, with a particular focus on the link between the molecular axis distribution and observable in various angle-integrated and angle-resolved measurements. To maintain generality the problem is treated geometrically, with the aligned ensemble cast in terms of axis distribution moments, and the response of observables in terms of couplings to these moments. Within this formalism the angular momentum coupling is treated analytically, allowing for general characteristics - independent of the details of the ionization dynamics of a specific molecule - to be determined. Limiting cases are explored in order to provide a phenomenology which should be readily applicable to a range of experimental measurements, and illustrate how observables can be sensitive to fine details of the alignment, i.e. higher-order moments of the axis distribution, which are often neglected in experimental studies. We hope that this detailed and comprehensive treatment will bridge the gap between existing theoretical and experimental works, and provide both quantitative physical insights and a useful general phenomenology for researchers working with aligned molecular ensembles. © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, Canada},
  Art_number               = {023069},
  Author_keywords          = {ionization; molecular alignment; multiphoton processes; photoelectron angular distributions},
  Document_type            = {Article},
  Doi                      = {10.1088/1367-2630/17/2/023069},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84924275584&partnerID=40&md5=634fffc76c24a4d0567d439e0f9bc10b}
}

Single and multi-photon ionization of aligned molecular ensembles is examined, with a particular focus on the link between the molecular axis distribution and observable in various angle-integrated and angle-resolved measurements. To maintain generality the problem is treated geometrically, with the aligned ensemble cast in terms of axis distribution moments, and the response of observables in terms of couplings to these moments. Within this formalism the angular momentum coupling is treated analytically, allowing for general characteristics - independent of the details of the ionization dynamics of a specific molecule - to be determined. Limiting cases are explored in order to provide a phenomenology which should be readily applicable to a range of experimental measurements, and illustrate how observables can be sensitive to fine details of the alignment, i.e. higher-order moments of the axis distribution, which are often neglected in experimental studies. We hope that this detailed and comprehensive treatment will bridge the gap between existing theoretical and experimental works, and provide both quantitative physical insights and a useful general phenomenology for researchers working with aligned molecular ensembles. © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

@Article{Hockett2015a,
  Title                    = {Maximum-information photoelectron metrology},
  Author                   = {Hockett, P.a , Lux, C.b , Wollenhaupt, M.c , Baumert, T.c },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2015},
  Number                   = {1},
  Volume                   = {92},

  Abstract                 = {Photoelectron interferograms, manifested in photoelectron angular distributions (PADs), are high-information, coherent observables. In order to obtain the maximum information from angle-resolved photoionization experiments it is desirable to record the full, three-dimensional (3D), photoelectron momentum distribution. Here we apply tomographic reconstruction techniques to obtain such 3D distributions from multiphoton ionization of potassium atoms, and fully analyze the energy and angular content of the 3D data. The PADs obtained as a function of energy indicate good agreement with previous 2D data and detailed analysis [Hockett, Phys. Rev. Lett. 112, 223001 (2014)10.1103/PhysRevLett.112.223001] concerning the main spectral features, but also indicate unexpected symmetry breaking in certain regions of momentum space, thus revealing additional continuum interferences which cannot otherwise be observed. These observations reflect the presence of additional ionization pathways and, most generally, illustrate the power of maximum-information measurements of coherent observables for quantum metrology of complex systems. © 2015 American Physical Society. ©2015 American Physical Society. ca.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, Canada; Institut für Physik, Universität Kassel, Heinrich-Plett-Straße 40, Kassel, Germany; Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Straße 9-11, Oldenburg, Germany},
  Art_number               = {013412},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.92.013412},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84938634665&partnerID=40&md5=0947ea28199f61b0b0e9672ff131b711}
}

Photoelectron interferograms, manifested in photoelectron angular distributions (PADs), are high-information, coherent observables. In order to obtain the maximum information from angle-resolved photoionization experiments it is desirable to record the full, three-dimensional (3D), photoelectron momentum distribution. Here we apply tomographic reconstruction techniques to obtain such 3D distributions from multiphoton ionization of potassium atoms, and fully analyze the energy and angular content of the 3D data. The PADs obtained as a function of energy indicate good agreement with previous 2D data and detailed analysis [Hockett, Phys. Rev. Lett. 112, 223001 (2014)10.1103/PhysRevLett.112.223001] concerning the main spectral features, but also indicate unexpected symmetry breaking in certain regions of momentum space, thus revealing additional continuum interferences which cannot otherwise be observed. These observations reflect the presence of additional ionization pathways and, most generally, illustrate the power of maximum-information measurements of coherent observables for quantum metrology of complex systems. © 2015 American Physical Society. ©2015 American Physical Society. ca.

@Article{Hockett2015c,
  Title                    = {Coherent control of photoelectron wavepacket angular interferograms},
  Author                   = {Hockett, P.a , Wollenhaupt, M.b , Baumert, T.c },
  Journal                  = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  Year                     = {2015},
  Number                   = {21},
  Volume                   = {48},

  Abstract                 = {Coherent control over photoelectron wavepackets, via the use of polarization-shaped laser pulses, can be understood as a time and polarization-multiplexed process, where the final (time-integrated) observable coherently samples all instantaneous states of the light-matter interaction. In this work, we investigate this multiplexing via computation of the observable photoelectron angular interferograms resulting from multi-photon atomic ionization with polarization-shaped laser pulses. We consider the polarization sensitivity of both the instantaneous and cumulative continuum wavefunction; the nature of the coherent control over the resultant photoelectron interferogram is thus explored in detail. Based on this understanding, the use of coherent control with polarization-shaped pulses as a methodology for a highly multiplexed coherent quantum metrology is also investigated, and defined in terms of the information content of the observable. © 2015 IOP Publishing Ltd.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, Canada; Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Straße 9-11, Oldenburg, Germany; Institut für Physik, Universität Kassel, Heinrich-Plett-Str. 40, Kassel, Germany},
  Art_number               = {214004},
  Author_keywords          = {coherent control; information content; metrology; photoelectron angular interferograms; photoionization; polarization-shaped pulses},
  Document_type            = {Article},
  Doi                      = {10.1088/0953-4075/48/21/214004},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84947460757&partnerID=40&md5=4db96f95c4c23a11db8dd3a00c8246f7}
}

Coherent control over photoelectron wavepackets, via the use of polarization-shaped laser pulses, can be understood as a time and polarization-multiplexed process, where the final (time-integrated) observable coherently samples all instantaneous states of the light-matter interaction. In this work, we investigate this multiplexing via computation of the observable photoelectron angular interferograms resulting from multi-photon atomic ionization with polarization-shaped laser pulses. We consider the polarization sensitivity of both the instantaneous and cumulative continuum wavefunction; the nature of the coherent control over the resultant photoelectron interferogram is thus explored in detail. Based on this understanding, the use of coherent control with polarization-shaped pulses as a methodology for a highly multiplexed coherent quantum metrology is also investigated, and defined in terms of the information content of the observable. © 2015 IOP Publishing Ltd.

@Article{Hockett2015b,
  Title                    = {Complete photoionization experiments via ultrafast coherent control with polarization multiplexing. II. Numerics and analysis methodologies},
  Author                   = {Hockett, P.a , Wollenhaupt, M.b , Lux, C.c , Baumert, T.c },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2015},
  Number                   = {1},
  Volume                   = {92},

  Abstract                 = {The feasibility of complete photoionization experiments, in which the full set of photoionization matrix elements is determined, using multiphoton ionization schemes with polarization-shaped pulses has recently been demonstrated [P. Hockett, Phys. Rev. Lett. 112, 223001 (2014)10.1103/PhysRevLett.112.223001]. Here we extend our previous work to discuss further details of the numerics and analysis methodology utilized and compare the results directly to new tomographic photoelectron measurements, which provide a more sensitive test of the validity of the results. In so doing we discuss in detail the physics of the photoionization process and suggest various avenues and prospects for this coherent multiplexing methodology. © 2015 American Physical Society. ©2015 American Physical Society. ca.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, Canada; Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Straße 9-11, Oldenburg, Germany; Institut für Physik, Universität Kassel, Heinrich-Plett-Str. 40, Kassel, Germany},
  Art_number               = {013411},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.92.013411},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84938650784&partnerID=40&md5=05f3e4b3c7b4e97ee401c56e542d9ca2}
}

The feasibility of complete photoionization experiments, in which the full set of photoionization matrix elements is determined, using multiphoton ionization schemes with polarization-shaped pulses has recently been demonstrated [P. Hockett, Phys. Rev. Lett. 112, 223001 (2014)10.1103/PhysRevLett.112.223001]. Here we extend our previous work to discuss further details of the numerics and analysis methodology utilized and compare the results directly to new tomographic photoelectron measurements, which provide a more sensitive test of the validity of the results. In so doing we discuss in detail the physics of the photoionization process and suggest various avenues and prospects for this coherent multiplexing methodology. © 2015 American Physical Society. ©2015 American Physical Society. ca.

@Article{Khazali2015,
  Title                    = {Photon-photon gate via the interaction between two collective Rydberg excitations},
  Author                   = {Khazali, M., Heshami, K., Simon, C.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2015},
  Number                   = {3},
  Volume                   = {91},

  Abstract                 = {We propose a scheme for a deterministic controlled-phase gate between two photons that is based on the strong interaction between two stationary collective Rydberg excitations in an atomic ensemble outside the regime of Rydberg blockade. The distance-dependent character of the interaction causes both a momentum displacement of the collective excitations and unwanted entanglement between them. We show that these effects can be overcome by swapping the collective excitations in space and by optimizing the geometry, resulting in a photon-photon gate with high fidelity and efficiency. © 2015 American Physical Society.},
  Affiliation              = {Institute for Quantum Science and Technology, Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada},
  Art_number               = {030301},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.91.030301},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84927511308&partnerID=40&md5=71eb8f74acace5d5c77046792d8470b0}
}

We propose a scheme for a deterministic controlled-phase gate between two photons that is based on the strong interaction between two stationary collective Rydberg excitations in an atomic ensemble outside the regime of Rydberg blockade. The distance-dependent character of the interaction causes both a momentum displacement of the collective excitations and unwanted entanglement between them. We show that these effects can be overcome by swapping the collective excitations in space and by optimizing the geometry, resulting in a photon-photon gate with high fidelity and efficiency. © 2015 American Physical Society.

@Article{Michelberger2015,
  Title                    = {Interfacing GHz-bandwidth heralded single photons with a warm vapour Raman memory},
  Author                   = {Michelberger, P.S.a , Champion, T.F.M.a , Sprague, M.R.a , Kaczmarek, K.T.a , Barbieri, M.a , Jin, X.M.a b , England, D.G.a c , Kolthammer, W.S.a , Saunders, D.J.a , Nunn, J.a , Walmsley, I.A.a },
  Journal                  = {New Journal of Physics},
  Year                     = {2015},
  Volume                   = {17},

  Abstract                 = {Broadband quantum memories, used as temporal multiplexers, are a key component in photonic quantum information processing, as they make repeat-until-success strategies scalable. We demonstrate a prototype system, operating on-demand, by interfacing a warm vapour, high time-bandwidth-product Raman memory with a travelling wave spontaneous parametric down-conversion source. We store single photons and observe a clear influence of the input photon statistics on the retrieved light, which we find currently to be limited by noise. We develop a theoretical model that identifies four-wave mixing as the sole important noise source and point towards practical solutions for noise-free operation. © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford, United Kingdom; Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China; National Research Council of Canada, Ottawa, ON, Canada},
  Art_number               = {043006},
  Author_keywords          = {quantum communication; quantum computer; quantum memory; Raman interaction; room-temperature; single photon storage; temporal multiplexer},
  Document_type            = {Article},
  Doi                      = {10.1088/1367-2630/17/4/043006},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84929602809&partnerID=40&md5=daa1e0f2ccc9b69865beeb80e8636624}
}

Broadband quantum memories, used as temporal multiplexers, are a key component in photonic quantum information processing, as they make repeat-until-success strategies scalable. We demonstrate a prototype system, operating on-demand, by interfacing a warm vapour, high time-bandwidth-product Raman memory with a travelling wave spontaneous parametric down-conversion source. We store single photons and observe a clear influence of the input photon statistics on the retrieved light, which we find currently to be limited by noise. We develop a theoretical model that identifies four-wave mixing as the sole important noise source and point towards practical solutions for noise-free operation. © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

@Conference{Bustard2014,
  Title                    = {A THz-bandwidth molecular memory for light},
  Author                   = {Bustard, P.J., England, D.G., Lausten, R., Sussman, B.J.},
  Year                     = {2014},

  Abstract                 = {We demonstrate a memory for light based on storing photons in the vibrations of hydrogen molecules. The THz-bandwidth memory is used to store 100-fs pulses for durations up to ~ 1ns, enabling ~ 10<sup>4</sup> operational time bins. © 2014 Optical Society of America.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada},
  Document_type            = {Conference Paper},
  Journal                  = {Laser Science, LS 2014},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84919776047&partnerID=40&md5=180cbe299891c172e28a83049835f02b}
}

We demonstrate a memory for light based on storing photons in the vibrations of hydrogen molecules. The THz-bandwidth memory is used to store 100-fs pulses for durations up to   1ns, enabling   10⁴ operational time bins. © 2014 Optical Society of America.

@Article{Decker2014,
  Title                    = {Canadian photonics: The foundation for a quantum leap},
  Author                   = {Decker, J.a , Tennant, J.b , Sussman, B.c },
  Journal                  = {Optics and Photonics News},
  Year                     = {2014},
  Number                   = {10},
  Pages                    = {18-20},
  Volume                   = {25},

  Abstract                 = {Stakeholders at the national and local levels are committed to advancing the field of quantum technologies in Canada. © 2014, Optical Society of American (OSA). All rights reserved.},
  Affiliation              = {Embassy of Canada, Berlin, Germany; W2N2 Partnership in OntarioON, Canada; National Research Council of Canada, Canada},
  Document_type            = {Short Survey},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84907989666&partnerID=40&md5=dc9794ff69267363b0fa6586f60f9250}
}

Stakeholders at the national and local levels are committed to advancing the field of quantum technologies in Canada. © 2014, Optical Society of American (OSA). All rights reserved.

@Article{England2014a,
  Title                    = {Efficient Raman generation in a waveguide: A route to ultrafast quantum random number generation},
  Author                   = {England, D.G., Bustard, P.J., Moffatt, D.J., Nunn, J., Lausten, R., Sussman, B.J.},
  Journal                  = {Applied Physics Letters},
  Year                     = {2014},
  Number                   = {5},
  Volume                   = {104},

  Abstract                 = {The inherent uncertainty in quantum mechanics offers a source of true randomness which can be used to produce unbreakable cryptographic keys. We discuss the development of a high-speed random number generator based on the quantum phase fluctuations in spontaneously initiated stimulated Raman scattering (SISRS). We utilize the tight confinement and long interaction length available in a Potassium Titanyl Phosphate waveguide to generate highly efficient SISRS using nanojoule pulse energies, reducing the high pump power requirements of the previous approaches. We measure the random phase of the Stokes output using a simple interferometric setup to yield quantum random numbers at 145 Mbps. © 2014 AIP Publishing LLC.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {051117},
  Document_type            = {Article},
  Doi                      = {10.1063/1.4864095},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84899809971&partnerID=40&md5=0f6420ec216cd17714797c9acfe5c9a4}
}

The inherent uncertainty in quantum mechanics offers a source of true randomness which can be used to produce unbreakable cryptographic keys. We discuss the development of a high-speed random number generator based on the quantum phase fluctuations in spontaneously initiated stimulated Raman scattering (SISRS). We utilize the tight confinement and long interaction length available in a Potassium Titanyl Phosphate waveguide to generate highly efficient SISRS using nanojoule pulse energies, reducing the high pump power requirements of the previous approaches. We measure the random phase of the Stokes output using a simple interferometric setup to yield quantum random numbers at 145 Mbps. © 2014 AIP Publishing LLC.

@Conference{England2014,
  Title                    = {A THz-bandwidth optical memory for quantum storage},
  Author                   = {England, D.G., Bustard, P.J., Sussman, B.J.},
  Year                     = {2014},
  Volume                   = {2014-January},

  Abstract                 = {We have demonstrated a THz-bandwidth quantum memory using the optical phonon modes of roomtemperature diamond [1]. A noise-floor of just 0.007 photons per pulse provides the opportunity to store photons produced by spontaneous parametric downconversion. © 2014 Optical Society of America.},
  Affiliation              = {National Research Council, 100 Sussex Drive, Ottawa, Canada},
  Art_number               = {6988432},
  Document_type            = {Conference Paper},
  Journal                  = {Conference on Lasers and Electro-Optics Europe - Technical Digest},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84944699513&partnerID=40&md5=ffd80ecdcbad6eec3a32a257280d7f6a}
}

We have demonstrated a THz-bandwidth quantum memory using the optical phonon modes of roomtemperature diamond [1]. A noise-floor of just 0.007 photons per pulse provides the opportunity to store photons produced by spontaneous parametric downconversion. © 2014 Optical Society of America.

@Conference{Heshami2014a,
  Title                    = {Raman quantum memory based on an ensemble of nitrogen-vacancy centers coupled to a microcavity},
  Author                   = {Heshami, K.a , Santori, C.b , Khanaliloo, B.a , Healey, C.a , Acosta, V.M.b , Barclay, P.E.a c , Simon, C.a },
  Year                     = {2014},
  Volume                   = {2014-January},

  Abstract                 = {We propose a scheme to realize quantum memories based on Raman coupling for storing photons in the electronic spin of NV- ensembles. We include all optical transitions in a 9-level configuration and evaluate the efficiencies. © 2014 Optical Society of America.},
  Affiliation              = {Institute for Quantum Science and Technology, Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; Hewlett Packard Laboratories, 1501 Page Mill Rd., Palo Alto, CA, United States; NRC National Institute for Nanotechnology, 11421 Saskatchewan Drive NW, Edmonton, AB, Canada},
  Art_number               = {6988431},
  Document_type            = {Conference Paper},
  Journal                  = {Conference on Lasers and Electro-Optics Europe - Technical Digest},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84944704783&partnerID=40&md5=6bede6a6574d144139c60cdca2531141}
}

We propose a scheme to realize quantum memories based on Raman coupling for storing photons in the electronic spin of NV- ensembles. We include all optical transitions in a 9-level configuration and evaluate the efficiencies. © 2014 Optical Society of America.

@Article{Heshami2014b,
  Title                    = {Raman quantum memory based on an ensemble of nitrogen-vacancy centers coupled to a microcavity},
  Author                   = {Heshami, K.a , Santori, C.b , Khanaliloo, B.a , Healey, C.a , Acosta, V.M.b , Barclay, P.E.a c , Simon, C.a },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2014},
  Number                   = {4},
  Volume                   = {89},

  Abstract                 = {We propose a scheme to realize optical quantum memories in an ensemble of nitrogen-vacancy centers in diamond that are coupled to a microcavity. The scheme is based on off-resonant Raman coupling, which allows one to circumvent optical inhomogeneous broadening and store optical photons in the electronic spin coherence. This approach promises a storage time of order 1 s and a time-bandwidth product of order 107. We include all possible optical transitions in a nine-level configuration, numerically evaluate the efficiencies, and discuss the requirements for achieving high efficiency and fidelity. © 2014 American Physical Society.},
  Affiliation              = {Institute for Quantum Science and Technology, Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4, Canada; Hewlett Packard Laboratories, 1501 Page Mill Rd., Palo Alto, Ca 94304, United States; NRC National Institute for Nanotechnology, 11421 Saskatchewan Drive NW, Edmonton, AB T6G 2M9, Canada},
  Art_number               = {040301},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.89.040301},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84907205386&partnerID=40&md5=3f620e3b21c6f155f40af37aef4f67f8}
}

We propose a scheme to realize optical quantum memories in an ensemble of nitrogen-vacancy centers in diamond that are coupled to a microcavity. The scheme is based on off-resonant Raman coupling, which allows one to circumvent optical inhomogeneous broadening and store optical photons in the electronic spin coherence. This approach promises a storage time of order 1 s and a time-bandwidth product of order 107. We include all possible optical transitions in a nine-level configuration, numerically evaluate the efficiencies, and discuss the requirements for achieving high efficiency and fidelity. © 2014 American Physical Society.

@Article{Hockett2014,
  Title                    = {Complete photoionization experiments via ultrafast coherent control with polarization multiplexing},
  Author                   = {Hockett, P.a b c , Wollenhaupt, M.a b c , Lux, C.a b c , Baumert, T.a b c },
  Journal                  = {Physical Review Letters},
  Year                     = {2014},
  Number                   = {22},
  Volume                   = {112},

  Abstract                 = {Photoelectron angular distributions (PADs) obtained from ionization of potassium atoms using moderately intense femtosecond IR fields (â1012Wcm-2) of various polarization states are shown to provide a route to "complete†photoionization experiments. Ionization occurs by a net three-photon absorption process, driven via the 4s 4p resonance at the one-photon level. A theoretical treatment incorporating the intrapulse electronic dynamics allows for a full set of ionization matrix elements to be extracted from 2D imaging data. 3D PADs generated from the extracted matrix elements are also compared to experimental, tomographically reconstructed, 3D photoelectron distributions, providing a sensitive test of their validity. Finally, application of the determined matrix elements to ionization via more complex, polarization-shaped, pulses is demonstrated, illustrating the utility of this methodology towards detailed understanding of complex ionization control schemes and suggesting the utility of such "multiplexed†intrapulse processes as powerful tools for measurement. © 2014 American Physical Society.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa K1M 1R6, Canada; Institut für Physik, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany; Institut für Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany},
  Art_number               = {223001},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.112.223001},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84902171393&partnerID=40&md5=f6736099cb2750e7e3b1cfea442c5733}
}

Photoelectron angular distributions (PADs) obtained from ionization of potassium atoms using moderately intense femtosecond IR fields (â1012Wcm-2) of various polarization states are shown to provide a route to "complete†photoionization experiments. Ionization occurs by a net three-photon absorption process, driven via the 4s 4p resonance at the one-photon level. A theoretical treatment incorporating the intrapulse electronic dynamics allows for a full set of ionization matrix elements to be extracted from 2D imaging data. 3D PADs generated from the extracted matrix elements are also compared to experimental, tomographically reconstructed, 3D photoelectron distributions, providing a sensitive test of their validity. Finally, application of the determined matrix elements to ionization via more complex, polarization-shaped, pulses is demonstrated, illustrating the utility of this methodology towards detailed understanding of complex ionization control schemes and suggesting the utility of such "multiplexed†intrapulse processes as powerful tools for measurement. © 2014 American Physical Society.

@Conference{Krovi2014a,
  Title                    = {Long range quantum key distribution using frequency multiplexing in broadband solid state memories},
  Author                   = {Krovi, H.a , Dutton, Z.a , Guha, S.a , Fuchs, C.a , Tittel, W.b , Simon, C.b , Slater, J.A.b , Heshami, K.b , Hedges, M.b , Kanter, G.S.c , Huang, Y.-P.c , Thiel, C.d },
  Year                     = {2014},

  Abstract                 = {We present simulations of rates for a quantum key distribution scheme using a frequency multiplexed repeater architecture with broadband solid-state quantum memories. We find that key can be generated over 1000 km with eight elementary links. © 2014 Optical Society of America.},
  Affiliation              = {Raytheon BBN Technologies, 10 Moulton Street, Cambridge, MA 02138, United States; University of Calgary, 2500 University Dr. NW, Calgary, AB, T2N 1N4, Canada; Northwestern University, 633 Clark Street, Evanston, IL 60208, United States; Montana State University, Bozeman, MT 59717, United States},
  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84905483112&partnerID=40&md5=af4ceb8af13655b8f903d276d91736d1}
}

We present simulations of rates for a quantum key distribution scheme using a frequency multiplexed repeater architecture with broadband solid-state quantum memories. We find that key can be generated over 1000 km with eight elementary links. © 2014 Optical Society of America.

@Conference{Michelberger2014,
  Title                    = {Heralded single photon storage in a room-temperature, broadband quantum memory},
  Author                   = {Michelberger, P.S.a , Nunn, J.a , Champion, T.F.M.a , Sprague, M.R.a , Kacmarek, K.a , Saunders, D.a , Kolthammer, W.S.a , Jin, X.-M.a , England, D.G.a b , Walmsley, I.A.a },
  Year                     = {2014},

  Abstract                 = {We demonstrate storage of heralded single photons in a room-temperature quantum memory, a key step towards scalable quantum networks. We evaluate the photon statistics of the stored photons and discuss limitations from four-wave mixing noise. © 2014 Optical Society of America.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU, United Kingdom; National Research Council of Canada, 100 Sussex Drive, Ottawa, K1A 0R6, Canada},
  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84905454742&partnerID=40&md5=c31a19eb8ce2052f47f480d61f8682a8}
}

We demonstrate storage of heralded single photons in a room-temperature quantum memory, a key step towards scalable quantum networks. We evaluate the photon statistics of the stored photons and discuss limitations from four-wave mixing noise. © 2014 Optical Society of America.

@Conference{Nunn2014,
  Title                    = {Storing GHz bandwidth heralded single photons in a room-temperature raman memory: Efficiency and noise},
  Author                   = {Nunn, J.a , Michelberger, P.S.a , Champion, T.F.M.a , Sprague, M.R.a , Kacmarek, K.a , Saunders, D.a , Kolthammer, W.S.a , Jin, X.-M.a , England, D.G.b , Walmsley, I.A.a },
  Year                     = {2014},

  Abstract                 = {We store GHz-bandwidth heralded single photons in a room-temperature Raman memory, which is a crucial primitive for scalable quantum photonics. We discuss methods to suppress four-wave mixing noise, which accompanies the retrieved photons. © 2014 Optical Society of America.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU, United Kingdom; National Research Council of Canada, 100 Sussex Drive, Ottawa, K1A 0R6, Canada},
  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84899728911&partnerID=40&md5=ea1f3b0c2430a70810eac23a0e287143}
}

We store GHz-bandwidth heralded single photons in a room-temperature Raman memory, which is a crucial primitive for scalable quantum photonics. We discuss methods to suppress four-wave mixing noise, which accompanies the retrieved photons. © 2014 Optical Society of America.

@Article{Saglamyurek2014,
  Title                    = {An integrated processor for photonic quantum states using a broadband light-matter interface},
  Author                   = {Saglamyurek, E., Sinclair, N., Slater, J.A., Heshami, K., Oblak, D., Tittel, W.},
  Journal                  = {New Journal of Physics},
  Year                     = {2014},
  Volume                   = {16},

  Abstract                 = {Faithful storage and coherent manipulation of quantum optical pulses are key for long distance quantum communications and quantum computing. Combining these functions in a light-matter interface that can be integrated on-chip with other photonic quantum technologies, e.g. sources of entangled photons, is an important step towards these applications. To date there have only been a few demonstrations of coherent pulse manipulation utilizing optical storage devices compatible with quantum states, and that only in atomic gas media (making integration difficult) and with limited capabilities. Here we describe how a broadband waveguide quantum memory based on the atomic frequency comb (AFC) protocol can be used as a programmable processor for essentially arbitrary spectral and temporal manipulations of individual quantum optical pulses. Using weak coherent optical pulses at the few photon level, we experimentally demonstrate sequencing, time-to-frequency multiplexing and demultiplexing, splitting, interfering, temporal and spectral filtering, compressing and stretching as well as selective delaying. Our integrated light-matter interface offers high-rate, robust and easily configurable manipulation of quantum optical pulses and brings fully practical optical quantum devices one step closer to reality. Furthermore, as the AFC protocol is suitable for storage of intense light pulses, our processor may also find applications in classical communications. © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.},
  Affiliation              = {Institute for Quantum Science and Technology, Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada},
  Art_number               = {065019},
  Author_keywords          = {atomic frequency comb; integrated optics; photonic processor; quantum communication; quantum computer; quantum memory},
  Document_type            = {Article},
  Doi                      = {10.1088/1367-2630/16/6/065019},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84903699724&partnerID=40&md5=2ae5106d50a4ae1ec1c1b06b3e8d29d6}
}

Faithful storage and coherent manipulation of quantum optical pulses are key for long distance quantum communications and quantum computing. Combining these functions in a light-matter interface that can be integrated on-chip with other photonic quantum technologies, e.g. sources of entangled photons, is an important step towards these applications. To date there have only been a few demonstrations of coherent pulse manipulation utilizing optical storage devices compatible with quantum states, and that only in atomic gas media (making integration difficult) and with limited capabilities. Here we describe how a broadband waveguide quantum memory based on the atomic frequency comb (AFC) protocol can be used as a programmable processor for essentially arbitrary spectral and temporal manipulations of individual quantum optical pulses. Using weak coherent optical pulses at the few photon level, we experimentally demonstrate sequencing, time-to-frequency multiplexing and demultiplexing, splitting, interfering, temporal and spectral filtering, compressing and stretching as well as selective delaying. Our integrated light-matter interface offers high-rate, robust and easily configurable manipulation of quantum optical pulses and brings fully practical optical quantum devices one step closer to reality. Furthermore, as the AFC protocol is suitable for storage of intense light pulses, our processor may also find applications in classical communications. © 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

@Article{Sprague2014,
  Title                    = {Broadband single-photon-level memory in a hollow-core photonic crystal fibre},
  Author                   = {Sprague, M.R.a , Michelberger, P.S.a , Champion, T.F.M.a , England, D.G.a d , Nunn, J.a , Jin, X.-M.a b , Kolthammer, W.S.a , Abdolvand, A.c , Russell, P.S.J.c , Walmsley, I.A.a },
  Journal                  = {Nature Photonics},
  Year                     = {2014},
  Number                   = {4},
  Pages                    = {287-291},
  Volume                   = {8},

  Abstract                 = {Storing information encoded in light is critical for realizing optical buffers for all-optical signal processing and quantum memories for quantum information processing. These proposals require efficient interaction between atoms and a well-defined optical mode. Photonic crystal fibres can enhance light-matter interactions and have engendered a broad range of nonlinear effects; however, the storage of light has proven elusive. Here, we report the first demonstration of an optical memory in a hollow-core photonic crystal fibre. We store gigahertz-bandwidth light in the hyperfine coherence of caesium atoms at room temperature using a far-detuned Raman interaction. We demonstrate a signal-to-noise ratio of 2.6:1 at the single-photon level and a memory efficiency of 27 ± 1%. Our results demonstrate the potential of a room-temperature fibre-integrated optical memory for implementing local nodes of quantum information networks. © 2014 Macmillan Publishers Limited. All rights reserved.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom; Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China; Max Planck Institute for the Science of Light, 91058 Erlangen, Germany; National Research Council of Canada, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada},
  Document_type            = {Article},
  Doi                      = {10.1038/nphoton.2014.45},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84897374161&partnerID=40&md5=a93604fae189717f7c4c017b8e876f55}
}

Storing information encoded in light is critical for realizing optical buffers for all-optical signal processing and quantum memories for quantum information processing. These proposals require efficient interaction between atoms and a well-defined optical mode. Photonic crystal fibres can enhance light-matter interactions and have engendered a broad range of nonlinear effects; however, the storage of light has proven elusive. Here, we report the first demonstration of an optical memory in a hollow-core photonic crystal fibre. We store gigahertz-bandwidth light in the hyperfine coherence of caesium atoms at room temperature using a far-detuned Raman interaction. We demonstrate a signal-to-noise ratio of 2.6:1 at the single-photon level and a memory efficiency of 27 ± 1%. Our results demonstrate the potential of a room-temperature fibre-integrated optical memory for implementing local nodes of quantum information networks. © 2014 Macmillan Publishers Limited. All rights reserved.

@Article{Wang2014,
  Title                    = {Time-resolved photoelectron spectra of CS2: Dynamics at conical intersections},
  Author                   = {Wang, K.a , McKoy, V.a , Hockett, P.a , Schuurman, M.S.b },
  Journal                  = {Physical Review Letters},
  Year                     = {2014},
  Number                   = {11},
  Volume                   = {112},

  Abstract                 = {We report results of the application of a fully ab initio approach for simulating time-resolved molecular-frame photoelectron angular distributions around conical intersections in CS2. The technique employs wave packet densities obtained with the multiple spawning method in conjunction with geometry- and energy-dependent photoionization matrix elements. The robust agreement of these results with measured molecular-frame photoelectron angular distributions for CS2 demonstrates that this technique can successfully elucidate, and disentangle, the underlying nuclear and photoionization dynamics around conical intersections in polyatomic molecules. © 2014 American Physical Society.},
  Affiliation              = {A. A. Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA 91125, United States; National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {113007},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.112.113007},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84897470775&partnerID=40&md5=0f54412c7109e24e23e5abba9abf4beb}
}

We report results of the application of a fully ab initio approach for simulating time-resolved molecular-frame photoelectron angular distributions around conical intersections in CS2. The technique employs wave packet densities obtained with the multiple spawning method in conjunction with geometry- and energy-dependent photoionization matrix elements. The robust agreement of these results with measured molecular-frame photoelectron angular distributions for CS2 demonstrates that this technique can successfully elucidate, and disentangle, the underlying nuclear and photoionization dynamics around conical intersections in polyatomic molecules. © 2014 American Physical Society.

@Article{Bustard2013,
  Title                    = {Toward quantum processing in molecules: A THz-bandwidth coherent memory for light},
  Author                   = {Bustard, P.J., Lausten, R., England, D.G., Sussman, B.J.},
  Journal                  = {Physical Review Letters},
  Year                     = {2013},
  Number                   = {8},
  Volume                   = {111},

  Abstract                 = {The unusual features of quantum mechanics are enabling the development of technologies not possible with classical physics. These devices utilize nonclassical phenomena in the states of atoms, ions, and solid-state media as the basis for many prototypes. Here we investigate molecular states as a distinct alternative. We demonstrate a memory for light based on storing photons in the vibrations of hydrogen molecules. The THz-bandwidth molecular memory is used to store 100-fs pulses for durations up to ∼1 ns, enabling ∼104 operational time bins. The results demonstrate the promise of molecules for constructing compact ultrafast quantum photonic technologies. Published by the American Physical Society.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {083901},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.111.083901},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84883170805&partnerID=40&md5=337badfbc110b3e7f72ec14fe08f929e}
}

The unusual features of quantum mechanics are enabling the development of technologies not possible with classical physics. These devices utilize nonclassical phenomena in the states of atoms, ions, and solid-state media as the basis for many prototypes. Here we investigate molecular states as a distinct alternative. We demonstrate a memory for light based on storing photons in the vibrations of hydrogen molecules. The THz-bandwidth molecular memory is used to store 100-fs pulses for durations up to ∼1 ns, enabling ∼104 operational time bins. The results demonstrate the promise of molecules for constructing compact ultrafast quantum photonic technologies. Published by the American Physical Society.

@Article{Bustard2013a,
  Title                    = {Quantum random bit generation using energy fluctuations in stimulated Raman scattering},
  Author                   = {Bustard, P.J.a , England, D.G.a , Nunn, J.a b , Moffatt, D.a , Spanner, M.a , Lausten, R.a , Sussman, B.J.a b },
  Journal                  = {Optics Express},
  Year                     = {2013},
  Number                   = {24},
  Pages                    = {29350-29357},
  Volume                   = {21},

  Abstract                 = {Random number sequences are a critical resource in modern information processing systems, with applications in cryptography, numerical simulation, and data sampling. We introduce a quantum random number generator based on the measurement of pulse energy quantum fluctuations in Stokes light generated by spontaneously-initiated stimulated Raman scattering. Bright Stokes pulse energy fluctuations up to five times the mean energy are measured with fast photodiodes and converted to unbiased random binary strings. Since the pulse energy is a continuous variable, multiple bits can be extracted from a single measurement. Our approach can be generalized to a wide range of Raman active materials; here we demonstrate a prototype using the optical phonon line in bulk diamond.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada; Department of Physics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada},
  Document_type            = {Article},
  Doi                      = {10.1364/OE.21.029350},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84890054819&partnerID=40&md5=0b3cbdb6f46816b6a858ba26ec9b528a}
}

Random number sequences are a critical resource in modern information processing systems, with applications in cryptography, numerical simulation, and data sampling. We introduce a quantum random number generator based on the measurement of pulse energy quantum fluctuations in Stokes light generated by spontaneously-initiated stimulated Raman scattering. Bright Stokes pulse energy fluctuations up to five times the mean energy are measured with fast photodiodes and converted to unbiased random binary strings. Since the pulse energy is a continuous variable, multiple bits can be extracted from a single measurement. Our approach can be generalized to a wide range of Raman active materials; here we demonstrate a prototype using the optical phonon line in bulk diamond.

@Article{England2013,
  Title                    = {From photons to phonons and back: A THz optical memory in diamond},
  Author                   = {England, D.G., Bustard, P.J., Nunn, J., Lausten, R., Sussman, B.J.},
  Journal                  = {Physical Review Letters},
  Year                     = {2013},
  Number                   = {24},
  Volume                   = {111},

  Abstract                 = {Optical quantum memories are vital for the scalability of future quantum technologies, enabling long-distance secure communication and local synchronization of quantum components. We demonstrate a THz-bandwidth memory for light using the optical phonon modes of a room temperature diamond. This large bandwidth makes the memory compatible with down-conversion-type photon sources. We demonstrate that four-wave mixing noise in this system is suppressed by material dispersion. The resulting noise floor is just 7×10-3 photons per pulse, which establishes that the memory is capable of storing single quanta. We investigate the principle sources of noise in this system and demonstrate that high material dispersion can be used to suppress four-wave mixing noise in Λ-type systems. Published by the American Physical Society.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {243601},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.111.243601},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84890291657&partnerID=40&md5=be46b4d739f3960ab15ea78141d52e45}
}

Optical quantum memories are vital for the scalability of future quantum technologies, enabling long-distance secure communication and local synchronization of quantum components. We demonstrate a THz-bandwidth memory for light using the optical phonon modes of a room temperature diamond. This large bandwidth makes the memory compatible with down-conversion-type photon sources. We demonstrate that four-wave mixing noise in this system is suppressed by material dispersion. The resulting noise floor is just 7×10-3 photons per pulse, which establishes that the memory is capable of storing single quanta. We investigate the principle sources of noise in this system and demonstrate that high material dispersion can be used to suppress four-wave mixing noise in Λ-type systems. Published by the American Physical Society.

@Conference{England2013a,
  Title                    = {Raman scattering for quantum technologies},
  Author                   = {England, D.G., Bustard, P.J., Nunn, J., Sussman, B.J.},
  Year                     = {2013},

  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84898638357&partnerID=40&md5=579c30e50207002c2237c563d46ab632}
}

@Article{Hockett2013,
  Title                    = {Probing ultrafast dynamics with time-resolved multi-dimensional coincidence imaging: Butadiene},
  Author                   = {Hockett, P.a , Ripani, E.b , Rytwinski, A.c , Stolow, A.a c },
  Journal                  = {Journal of Modern Optics},
  Year                     = {2013},
  Number                   = {17},
  Pages                    = {1409-1425},
  Volume                   = {60},

  Abstract                 = {Time-resolved coincidence imaging of photoelectrons and photoions represents the most complete experimental measurement of ultrafast excited state dynamics, a multi-dimensional measurement for a multi-dimensional problem. Here we present the experimental data from recent coincidence imaging experiments, undertaken with the aim of gaining insight into the complex ultrafast excited-state dynamics of 1,3-butadiene initiated by absorption of 200 nm light. We discuss photoion and photoelectron mappings of increasing dimensionality, and focus particularly on the time-resolved photoelectron angular distributions (TRPADs), expected to be a sensitive probe of the electronic evolution of the excited state and to provide significant information beyond the time-resolved photoelectron spectrum (TRPES). Complex temporal behaviour is observed in the TRPADs, revealing their sensitivity to the dynamics while also emphasising the difficulty of interpretation of these complex observables. From the experimental data some details of the wavepacket dynamics are discerned relatively directly, and we make some tentative comparisons with existing ab initio calculations in order to gain deeper insight into the experimental measurements; finally, we sketch out some considerations for taking this comparison further in order to bridge the gap between experiment and theory. © 2013, Taylor & Francis.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada; Dipartimento di Chimica, Università La Sapienza, Piazzale Aldo Moro 5, Rome, Italy; Department of Chemistry, Queens University, Kingston, ON, Canada},
  Author_keywords          = {Butadiene; Coincidence imaging; Photoionization; Time-resolved photoelectron angular distributions (TRPADs); Time-resolved photoelectron spectroscopy (TRPES); Ultrafast dynamics},
  Document_type            = {Article},
  Doi                      = {10.1080/09500340.2013.801525},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84890859229&partnerID=40&md5=65ee2c713c9008b85885d652e6417c57}
}

Time-resolved coincidence imaging of photoelectrons and photoions represents the most complete experimental measurement of ultrafast excited state dynamics, a multi-dimensional measurement for a multi-dimensional problem. Here we present the experimental data from recent coincidence imaging experiments, undertaken with the aim of gaining insight into the complex ultrafast excited-state dynamics of 1,3-butadiene initiated by absorption of 200 nm light. We discuss photoion and photoelectron mappings of increasing dimensionality, and focus particularly on the time-resolved photoelectron angular distributions (TRPADs), expected to be a sensitive probe of the electronic evolution of the excited state and to provide significant information beyond the time-resolved photoelectron spectrum (TRPES). Complex temporal behaviour is observed in the TRPADs, revealing their sensitivity to the dynamics while also emphasising the difficulty of interpretation of these complex observables. From the experimental data some details of the wavepacket dynamics are discerned relatively directly, and we make some tentative comparisons with existing ab initio calculations in order to gain deeper insight into the experimental measurements; finally, we sketch out some considerations for taking this comparison further in order to bridge the gap between experiment and theory. © 2013, Taylor & Francis.

@Article{Kaviani2013,
  Title                    = {Quantum storage and retrieval of light by sweeping the atomic frequency},
  Author                   = {Kaviani, H., Khazali, M., Ghobadi, R., Zahedinejad, E., Heshami, K., Simon, C.},
  Journal                  = {New Journal of Physics},
  Year                     = {2013},
  Volume                   = {15},

  Abstract                 = {We propose a quantum memory protocol based on dynamically changing the resonance frequency of an ensemble of two-level atoms. By sweeping the atomic frequency in an adiabatic fashion, photons are reversibly transferred into atomic coherences. We present a polaritonic description for this type of storage, which shares some similarities with electromagnetically induced transparency based quantum memories. On the other hand the proposed memory is also linked to the gradient echo memory due to the effective spatial gradient that pulses experience in the medium. We discuss a possible implementation of the protocol in hollow-core photonic crystal fibers. © IOP Publishing and Deutsche Physikalische Gesellschaft.},
  Affiliation              = {Institute for Quantum Science and Technology, Department of Physics and Astronomy, University of Calgary, AB, T2N 1N4, Canada},
  Art_number               = {085029},
  Document_type            = {Article},
  Doi                      = {10.1088/1367-2630/15/8/085029},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84883417607&partnerID=40&md5=47b7d89be58aeb2ec689169194a7fbb7}
}

We propose a quantum memory protocol based on dynamically changing the resonance frequency of an ensemble of two-level atoms. By sweeping the atomic frequency in an adiabatic fashion, photons are reversibly transferred into atomic coherences. We present a polaritonic description for this type of storage, which shares some similarities with electromagnetically induced transparency based quantum memories. On the other hand the proposed memory is also linked to the gradient echo memory due to the effective spatial gradient that pulses experience in the medium. We discuss a possible implementation of the protocol in hollow-core photonic crystal fibers. © IOP Publishing and Deutsche Physikalische Gesellschaft.

@Article{Nunn2013,
  Title                    = {Enhancing multiphoton rates with quantum memories},
  Author                   = {Nunn, J.a , Langford, N.K.b , Kolthammer, W.S.a , Champion, T.F.M.a , Sprague, M.R.a , Michelberger, P.S.a , Jin, X.-M.a c , England, D.G.a , Walmsley, I.A.a },
  Journal                  = {Physical Review Letters},
  Year                     = {2013},
  Number                   = {13},
  Volume                   = {110},

  Abstract                 = {Single photons are a vital resource for optical quantum information processing. Efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using nondeterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this "scaling catastrophe." Here, we analyze in detail the benefits of quantum memories for producing multiphoton states, showing how the production rates can be enhanced by many orders of magnitude. We identify the quantity ηB as the most important figure of merit in this connection, where η and B are the efficiency and time-bandwidth product of the memories, respectively. © 2013 American Physical Society.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom; Department of Physics, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom; Centre for Quantum Technologies, National University of Singapore, 117543 Singapore, Singapore},
  Art_number               = {133601},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.110.133601},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84875421248&partnerID=40&md5=c9e34bd3eae3f052ddd38192bde8f0a3}
}

Single photons are a vital resource for optical quantum information processing. Efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using nondeterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this "scaling catastrophe." Here, we analyze in detail the benefits of quantum memories for producing multiphoton states, showing how the production rates can be enhanced by many orders of magnitude. We identify the quantity ηB as the most important figure of merit in this connection, where η and B are the efficiency and time-bandwidth product of the memories, respectively. © 2013 American Physical Society.

@Conference{Nunn2013a,
  Title                    = {Towards scalable photonics via quantum storage},
  Author                   = {Nunn, J.a , Langford, N.K.b , Kolthammer, W.S.a , Champion, T.F.M.a , Sprague, M.R.a , Michelberger, P.S.a , Jin, X.-M.a c , England, D.G.d , Walmsley, I.A.a },
  Year                     = {2013},
  Volume                   = {8636},

  Abstract                 = {Single photons are a vital resource for optical quantum information processing. efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using non-deterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this 'scaling catastrophe'. Here, we analyze two protocols for generating multiphoton states using quantum memories, showing how the production rates can be enhanced by many orders of magnitude. We identify the time-bandwidth product as a key figure of merit in this connection. © 2013 SPIE.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom; Department of Physics, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom; Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore; National Research Council Canada, 100 Sussex Drive, Ottawa, ON K1A OR6, Canada},
  Art_number               = {863612},
  Author_keywords          = {Broadband storage; Cesium vapour; Quantum computing; Quantum information processing; Quantum memories; Raman scattering; Single photons; Synchronisation},
  Document_type            = {Conference Paper},
  Doi                      = {10.1117/12.2012487},
  Journal                  = {Proceedings of SPIE - The International Society for Optical Engineering},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84878316491&partnerID=40&md5=e00387b5dde068f9d343497fca699090}
}

Single photons are a vital resource for optical quantum information processing. efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using non-deterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this 'scaling catastrophe'. Here, we analyze two protocols for generating multiphoton states using quantum memories, showing how the production rates can be enhanced by many orders of magnitude. We identify the time-bandwidth product as a key figure of merit in this connection. © 2013 SPIE.

@Conference{Nunn2013b,
  Title                    = {Quantum memories and large-scale quantum coherence based on Raman interactions},
  Author                   = {Nunn, J.a , Sprague, M.R.a , Michelberger, P.S.a , Champion, T.F.M.a , Jin, X.-M.a , Langford, N.K.b , Sussman, B.J.c , England, D.G.c , Barbieri, M.a , Kolthammer, W.S.a , Walmsley, I.A.a },
  Year                     = {2013},
  Pages                    = {173-174},

  Abstract                 = {Applied research into quantum technologies and fundamental research into the foundations of quantum mechanics run hand in hand, since our understanding of quantum correlations both advances, and is advanced by, our ability to control large quantum systems. The off-resonant Raman interaction of light with material systems provides a powerful tool both for quantum information processing, and for accessing macroscopic non-classical states of matter. We describe a recent demonstration of entanglement between the motion of separated diamond crystals at room temperature, and the implementation of quantum memories in cesium vapour that can store and retrieve photons on demand with a time-bandwidth product exceeding 2000, both based on Raman scattering. © 2013 IEEE.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, United Kingdom; Department of Physics, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom; National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {6614558},
  Document_type            = {Conference Paper},
  Doi                      = {10.1109/PHOSST.2013.6614558},
  Journal                  = {2013 IEEE Photonics Society Summer Topical Meeting Series, PSSTMS 2013},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84887432470&partnerID=40&md5=aaafc80a58e243c692fdbc9fc64c26fa}
}

Applied research into quantum technologies and fundamental research into the foundations of quantum mechanics run hand in hand, since our understanding of quantum correlations both advances, and is advanced by, our ability to control large quantum systems. The off-resonant Raman interaction of light with material systems provides a powerful tool both for quantum information processing, and for accessing macroscopic non-classical states of matter. We describe a recent demonstration of entanglement between the motion of separated diamond crystals at room temperature, and the implementation of quantum memories in cesium vapour that can store and retrieve photons on demand with a time-bandwidth product exceeding 2000, both based on Raman scattering. © 2013 IEEE.

@Article{Sprague2013a,
  Title                    = {Efficient optical pumping and high optical depth in a hollow-core photonic-crystal fibre for a broadband quantum memory},
  Author                   = {Sprague, M.R.a , England, D.G.a d , Abdolvand, A.b , Nunn, J.a , Jin, X.-M.a , Steven Kolthammer, W.a , Barbieri, M.a , Rigal, B.c , Michelberger, P.S.a , Champion, T.F.M.a , Russell, P.S.J.b , Walmsley, I.A.a },
  Journal                  = {New Journal of Physics},
  Year                     = {2013},
  Volume                   = {15},

  Abstract                 = {The generation of large multiphoton quantum states - for applications in computing, metrology and simulation - requires a network of high-efficiency quantum memories capable of storing broadband pulses. Integrating these memories into a fibre offers a number of advantages towards realizing this goal: strong light-matter coupling at low powers, simplified alignment and compatibility with existing photonic architectures. Here, we introduce a large-core kagome-structured hollow-core fibre as a suitable platform for an integrated fibre-based quantum memory with a warm atomic vapour. We demonstrate, for the first time, efficient optical pumping in such a system, where 90 ± 1% of atoms are prepared in the ground state. We measure high optical depths (3 × 104) and narrow homogeneous linewidths (6 ± 2 MHz) that do not exhibit significant transit-time broadening, showing that we can prepare a Λ-level system in a pure state. Our results establish that kagome fibres are suitable for implementing a broadband, room-temperature quantum memory, as well as a range of nonlinear optical effects. © IOP Publishing and Deutsche Physikalische Gesellschaft.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, OX1 3PU Oxford, United Kingdom; Max Planck Institute for the Science of Light, Guenther-Scharowsky Straße 1, D-91058 Erlangen, Germany; École Polytechnique, Route de Saclay, 91120 Palaiseau, France; National Research Council Canada, 100 Sussex Drive, Ottawa K1A 0R6, Canada},
  Art_number               = {055013},
  Document_type            = {Article},
  Doi                      = {10.1088/1367-2630/15/5/055013},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84878222338&partnerID=40&md5=c5c6ac0690dd9dc23aec09903962e05d}
}

The generation of large multiphoton quantum states - for applications in computing, metrology and simulation - requires a network of high-efficiency quantum memories capable of storing broadband pulses. Integrating these memories into a fibre offers a number of advantages towards realizing this goal: strong light-matter coupling at low powers, simplified alignment and compatibility with existing photonic architectures. Here, we introduce a large-core kagome-structured hollow-core fibre as a suitable platform for an integrated fibre-based quantum memory with a warm atomic vapour. We demonstrate, for the first time, efficient optical pumping in such a system, where 90 ± 1% of atoms are prepared in the ground state. We measure high optical depths (3 × 104) and narrow homogeneous linewidths (6 ± 2 MHz) that do not exhibit significant transit-time broadening, showing that we can prepare a Λ-level system in a pure state. Our results establish that kagome fibres are suitable for implementing a broadband, room-temperature quantum memory, as well as a range of nonlinear optical effects. © IOP Publishing and Deutsche Physikalische Gesellschaft.

@Conference{Sprague2013,
  Title                    = {Storage of light in a hollow-core photonic-crystal fibre},
  Author                   = {Sprague, M.R.a , Michelberger, P.a , Champion, T.F.M.a , England, D.G.a , Nunn, J.a , Kolthammer, W.S.a , Jin, X.-M.a , Abdolvand, A.b , Russell, P.S.J.b , Walmsley, I.A.a },
  Year                     = {2013},

  Abstract                 = {We report the storage and retrieval of broadband optical pulses using a Raman interaction in a room-temperature ensemble of cesium atoms confined in a hollow-core photonic-crystal fibre. © 2013 The Optical Society.},
  Affiliation              = {Clarendon Laboratory, Department of Physics, University of Oxford, Parks Rd, Oxford OX1 3PU, United Kingdom; Max Planck Institute for the Science of Light, Guenther-Scharowsky Str. 1, 91058 Erlangen, Germany},
  Art_number               = {6834454},
  Document_type            = {Conference Paper},
  Journal                  = {2013 Conference on Lasers and Electro-Optics, CLEO 2013},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84903779190&partnerID=40&md5=72df320b8289d8c11a70b290cc143439}
}

We report the storage and retrieval of broadband optical pulses using a Raman interaction in a room-temperature ensemble of cesium atoms confined in a hollow-core photonic-crystal fibre. © 2013 The Optical Society.

@Article{Walmsley2013,
  Title                    = {Entang-bling: Observing quantum correlations in room-temperature solids},
  Author                   = {Walmsley, I.A., Lee, K.C., Sprague, M., Sussman, B., Nunn, J., Langford, N., Jin, X.-M., Champion, T., Michelberger, P., Reim, K., England, D., Jaksch, D.},
  Journal                  = {Journal of Physics: Conference Series},
  Year                     = {2013},
  Number                   = {1},
  Volume                   = {442},

  Abstract                 = {Quantum entanglement in the motion of macroscopic solid bodies has implications both for quantum technologies and foundational studies of the boundary between the quantum and classical worlds. Entanglement is usually fragile in room-temperature solids, owing to strong interactions both internally and with the noisy environment. We generated motional entanglement between vibrational states of two spatially separated, millimeter-sized diamonds at room temperature. By measuring strong nonclassical correlations between Raman-scattered photons, we showed that the quantum state of the diamonds has positive concurrence with 98% probability. Our results show that entanglement can persist in the classical context of moving macroscopic solids in ambient conditions. © Published under licence by IOP Publishing Ltd.},
  Affiliation              = {University of Oxford, Department of Physics, Clarendon Laboratory, Parks Rd, Oxford, OX3 0BU, United Kingdom},
  Art_number               = {012004},
  Document_type            = {Conference Paper},
  Doi                      = {10.1088/1742-6596/442/1/012004},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84881439564&partnerID=40&md5=d1599399e71717f7094c3a5818edf14a}
}

Quantum entanglement in the motion of macroscopic solid bodies has implications both for quantum technologies and foundational studies of the boundary between the quantum and classical worlds. Entanglement is usually fragile in room-temperature solids, owing to strong interactions both internally and with the noisy environment. We generated motional entanglement between vibrational states of two spatially separated, millimeter-sized diamonds at room temperature. By measuring strong nonclassical correlations between Raman-scattered photons, we showed that the quantum state of the diamonds has positive concurrence with 98% probability. Our results show that entanglement can persist in the classical context of moving macroscopic solids in ambient conditions. © Published under licence by IOP Publishing Ltd.

@Article{Bertrand2012,
  Title                    = {Revealing the cooper minimum of N 2 by molecular frame high-harmonic spectroscopy},
  Author                   = {Bertrand, J.B.a , Wörner, H.J.b , Hockett, P.a , Villeneuve, D.M.a , Corkum, P.B.a },
  Journal                  = {Physical Review Letters},
  Year                     = {2012},
  Number                   = {14},
  Volume                   = {109},

  Abstract                 = {Molecular frame high-harmonic spectra of aligned N 2 molecules reveal a Cooper-like minimum. By deconvolving the laboratory frame alignment distribution, what was previously thought to be a maximum of emission along the molecular axis is found to be maxima at 35 degrees off axis, with a spectral minimum on axis. Both of these features are supported by photoionization calculations that underline the relationship between high-harmonic spectroscopy and photoionization measurements. The calculations reveal that the on axis spectral minimum is a Cooper-like minimum that arises from the destructive interference of the p and f partial wave contributions to high-harmonic photorecombination. Features such as Cooper minima and shape resonances are ubiquitous in molecular photoionization or recombination. Published by the American Physical Society. © Published by the American Physical Society.},
  Affiliation              = {Joint Attosecond Science Laboratory, National Research Council of Canada, University of Ottawa, 100 Sussex Drive, Ottawa, K1A 0R6, Canada; Laboratorium für Physikalische Chemie, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland},
  Art_number               = {143001},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.109.143001},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84867060251&partnerID=40&md5=9c5158fadf5d3af58c24a34b285bcf97}
}

Molecular frame high-harmonic spectra of aligned N 2 molecules reveal a Cooper-like minimum. By deconvolving the laboratory frame alignment distribution, what was previously thought to be a maximum of emission along the molecular axis is found to be maxima at 35 degrees off axis, with a spectral minimum on axis. Both of these features are supported by photoionization calculations that underline the relationship between high-harmonic spectroscopy and photoionization measurements. The calculations reveal that the on axis spectral minimum is a Cooper-like minimum that arises from the destructive interference of the p and f partial wave contributions to high-harmonic photorecombination. Features such as Cooper minima and shape resonances are ubiquitous in molecular photoionization or recombination. Published by the American Physical Society. © Published by the American Physical Society.

@Article{Bustard2012,
  Title                    = {Molecular alignment and orientation with a hybrid Raman scattering technique},
  Author                   = {Bustard, P.J., Lausten, R., Sussman, B.J.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2012},
  Number                   = {5},
  Volume                   = {86},

  Abstract                 = {We demonstrate a scheme for the preparation of molecular alignment and angular momentum orientation using a hybrid combination of two limits of Raman scattering. First a weak, impulsive pump pulse initializes the system via the nonresonant dynamic Stark effect. Then, having overcome the influence of the vacuum fluctuations, an amplification pulse selectively enhances the initial coherences by transient stimulated Raman scattering, generating alignment and angular momentum orientation of molecular hydrogen. The amplitude and phase of the resulting coherent dynamics are experimentally probed, indicating an amplification factor of 4.5. An analytic theory is developed to model the dynamics. Published by the American Physical Society.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {053419},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.86.053419},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84870410606&partnerID=40&md5=5ba48d5e46d6c92771c1797ae615d517}
}

We demonstrate a scheme for the preparation of molecular alignment and angular momentum orientation using a hybrid combination of two limits of Raman scattering. First a weak, impulsive pump pulse initializes the system via the nonresonant dynamic Stark effect. Then, having overcome the influence of the vacuum fluctuations, an amplification pulse selectively enhances the initial coherences by transient stimulated Raman scattering, generating alignment and angular momentum orientation of molecular hydrogen. The amplitude and phase of the resulting coherent dynamics are experimentally probed, indicating an amplification factor of 4.5. An analytic theory is developed to model the dynamics. Published by the American Physical Society.

@Conference{Bustard2012a,
  Title                    = {Raman scattering: A coherent mediator for quantum technologies},
  Author                   = {Bustard, P.J., Lausten, R., Sussman, B.J.},
  Year                     = {2012},

  Abstract                 = {Stimulated Raman scattering (SRS) is a powerful tool for the manipulation and articulation of quantum systems. I will discuss SRS as a tool to mediate the transfer of coherencebetween light and matter, and describe some practical applications in the development of quantum technologies. © OSA 2012.},
  Affiliation              = {National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, K1A 0R6, Canada},
  Document_type            = {Conference Paper},
  Journal                  = {Laser Science, LS 2012},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84893035724&partnerID=40&md5=58ebba71ea1662cede45cf5d040f373e}
}

Stimulated Raman scattering (SRS) is a powerful tool for the manipulation and articulation of quantum systems. I will discuss SRS as a tool to mediate the transfer of coherencebetween light and matter, and describe some practical applications in the development of quantum technologies. © OSA 2012.

@Conference{Bustard2012c,
  Title                    = {Quantum random bit generation by stimulated Raman scattering},
  Author                   = {Bustard, P.J.a , Moffatt, D.a , Lausten, R.a , Wu, G.a , Walmsley, I.A.b , Sussman, B.J.a },
  Year                     = {2012},

  Abstract                 = {We introduce a quantum random number generator based on the phase measurement of Stokes light generated by amplification of zero-point vacuum fluctuations using stimulated Raman scattering in bulk diamond. © 2012 OSA.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada; Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom},
  Art_number               = {6326885},
  Document_type            = {Conference Paper},
  Journal                  = {2012 Conference on Lasers and Electro-Optics, CLEO 2012},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84870356633&partnerID=40&md5=d1ca3ae6ccbf895b05dee3427c446327}
}

We introduce a quantum random number generator based on the phase measurement of Stokes light generated by amplification of zero-point vacuum fluctuations using stimulated Raman scattering in bulk diamond. © 2012 OSA.

@Article{Clark2012,
  Title                    = {Photonic quantum memory in two-level ensembles based on modulating the refractive index in time: Equivalence to gradient echo memory},
  Author                   = {Clark, J., Heshami, K., Simon, C.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2012},
  Number                   = {1},
  Volume                   = {86},

  Abstract                 = {We present a quantum memory protocol that allows us to store light in ensembles of two-level atoms, e.g., rare-earth-metal ions doped into a crystal, by modulating the refractive index of the host medium of the atoms linearly in time. We show that under certain conditions the resulting dynamics is equivalent to that underlying the gradient echo memory protocol, which relies on a spatial gradient of the atomic resonance frequencies. We discuss the prospects for an experimental implementation. © 2012 American Physical Society.},
  Affiliation              = {Institute for Quantum Information Science, Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4, Canada},
  Art_number               = {013833},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.86.013833},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84864189787&partnerID=40&md5=084eddd207f603ee76a40bab34003372}
}

We present a quantum memory protocol that allows us to store light in ensembles of two-level atoms, e.g., rare-earth-metal ions doped into a crystal, by modulating the refractive index of the host medium of the atoms linearly in time. We show that under certain conditions the resulting dynamics is equivalent to that underlying the gradient echo memory protocol, which relies on a spatial gradient of the atomic resonance frequencies. We discuss the prospects for an experimental implementation. © 2012 American Physical Society.

@Article{England2012,
  Title                    = {High-fidelity polarization storage in a gigahertz bandwidth quantum memory},
  Author                   = {England, D.G.a , Michelberger, P.S.a , Champion, T.F.M.a , Reim, K.F.a c , Lee, K.C.a , Sprague, M.R.a , Jin, X.-M.a b , Langford, N.K.a d , Kolthammer, W.S.a , Nunn, J.a , Walmsley, I.A.a },
  Journal                  = {Journal of Physics B: Atomic, Molecular and Optical Physics},
  Year                     = {2012},
  Number                   = {12},
  Volume                   = {45},

  Abstract                 = {We demonstrate a dual-rail optical Raman memory inside a polarization interferometer; this enables us to store polarization-encoded information at GHz bandwidths in a room-temperature atomic ensemble. By performing full process tomography on the system, we measure up to 97 ± 1% process fidelity for the storage and retrieval process. At longer storage times, the process fidelity remains high, despite a loss of efficiency. The fidelity is 86 ± 4% for 1.5 μs storage time, which is 5000 times the pulse duration. Hence, high fidelity is combined with a large time-bandwidth product. This high performance, with an experimentally simple setup, demonstrates the suitability of the Raman memory for integration into large-scale quantum networks. © 2012 IOP Publishing Ltd.},
  Affiliation              = {Department of Physics, Clarendon Laboratory, University of Oxford, Oxford OX1 3PU, United Kingdom; Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore; Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland; Department of Physics, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom},
  Art_number               = {124008},
  Document_type            = {Article},
  Doi                      = {10.1088/0953-4075/45/12/124008},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84862225020&partnerID=40&md5=84e9b7ffd5f9cafe50a6641a1ea4586f}
}

We demonstrate a dual-rail optical Raman memory inside a polarization interferometer; this enables us to store polarization-encoded information at GHz bandwidths in a room-temperature atomic ensemble. By performing full process tomography on the system, we measure up to 97 ± 1% process fidelity for the storage and retrieval process. At longer storage times, the process fidelity remains high, despite a loss of efficiency. The fidelity is 86 ± 4% for 1.5 μs storage time, which is 5000 times the pulse duration. Hence, high fidelity is combined with a large time-bandwidth product. This high performance, with an experimentally simple setup, demonstrates the suitability of the Raman memory for integration into large-scale quantum networks. © 2012 IOP Publishing Ltd.

@Article{Frumker2012c,
  Title                    = {Erratum: Probing Polar Molecules with High Harmonic Spectroscopy (Physical Review Letters (2012) 109 (233904)},
  Author                   = {Frumker, E., Kajumba, N., Bertrand, J.B., Wörner, H.J., Hebeisen, C.T., Hockett, P., Spanner, M., Patchkovskii, S., Paulus, G.G., Villeneuve, D.M., Naumov, A., Corkum, P.B.},
  Journal                  = {Physical Review Letters},
  Year                     = {2012},
  Number                   = {24},
  Volume                   = {109},

  Art_number               = {249902},
  Document_type            = {Erratum},
  Doi                      = {10.1103/PhysRevLett.109.249902},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84871320360&partnerID=40&md5=6c4a6c23068e6cb0c0b09cf131860e7d}
}

@Article{Frumker2012a,
  Title                    = {Probing polar molecules with high harmonic spectroscopy},
  Author                   = {Frumker, E.a b c , Kajumba, N.a , Bertrand, J.B.a , Wörner, H.J.a , Hebeisen, C.T.a , Hockett, P.d , Spanner, M.d , Patchkovskii, S.d , Paulus, G.G.c , Villeneuve, D.M.a , Naumov, A.a , Corkum, P.B.a },
  Journal                  = {Physical Review Letters},
  Year                     = {2012},
  Number                   = {23},
  Volume                   = {109},

  Abstract                 = {We bring the methodology of orienting polar molecules together with the phase sensitivity of high harmonic spectroscopy to experimentally compare the phase difference of attosecond bursts of radiation emitted upon electron recollision from different ends of a polar molecule. This phase difference has an impact on harmonics from aligned polar molecules, suppressing emission from the molecules parallel to the driving laser field while favoring the perpendicular ones. For oriented molecules, we measure the amplitude ratio of even to odd harmonics produced when intense light irradiates CO molecules and determine the degree of orientation and the phase difference of attosecond bursts using molecular frame ionization and recombination amplitudes. The sensitivity of the high harmonic spectrum to subtle phase differences in the emitted radiation makes it a detailed probe of polar molecules and will drive major advances in the theory of high harmonic generation. © 2012 American Physical Society.},
  Affiliation              = {Joint Attosecond Science Laboratory, University of Ottawa and National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada; Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany; Department of Physics, Texas A and M University, College Station, TX 77843, United States; Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {233904},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.109.233904},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84870585623&partnerID=40&md5=9a0bba69ad19a0dece3c8be00ef24325}
}

We bring the methodology of orienting polar molecules together with the phase sensitivity of high harmonic spectroscopy to experimentally compare the phase difference of attosecond bursts of radiation emitted upon electron recollision from different ends of a polar molecule. This phase difference has an impact on harmonics from aligned polar molecules, suppressing emission from the molecules parallel to the driving laser field while favoring the perpendicular ones. For oriented molecules, we measure the amplitude ratio of even to odd harmonics produced when intense light irradiates CO molecules and determine the degree of orientation and the phase difference of attosecond bursts using molecular frame ionization and recombination amplitudes. The sensitivity of the high harmonic spectrum to subtle phase differences in the emitted radiation makes it a detailed probe of polar molecules and will drive major advances in the theory of high harmonic generation. © 2012 American Physical Society.

@Conference{Frumker2012b,
  Title                    = {Attosecond pulse trains generated with oriented molecules},
  Author                   = {Frumker, E.a c e , Kajumba, N.a e f , Bertrand, J.B.a , Worner, H.J.a g , Hebeisen, C.T.a , Hockett, P.b , Spanner, M.b , Patchkovskii, S.b , Paulus, G.G.c d , Villeneuve, D.M.a , Corkum, P.B.a },
  Year                     = {2012},

  Abstract                 = {We report the measurement of high harmonics from oriented molecules in the gas phase. We show that attosecond and re-collision science provides a detailed and sensitive probe of electronic asymmetry in polar molecules. © 2012 OSA.},
  Affiliation              = {Joint Laboratory for Attosecond Science, National Research Council of Canada, University of Ottawa, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada; Steacie Institute for Molecular Science, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON, Canada; Department of Physics, Texas A and M University, College Station, TX 77843, United States; Institute of Optics and Quantum Electronics, Max-Wien-Platz 1, Jena 07743, Germany; Max-Planck-Institut fur Quantenoptik, D-85748 Garching, Germany; Department fur Physik, Ludwig-Maximilians-Universitat, D-80799 Munich, Germany; Laboratorium fur Physikalische Chemie, ETH Zurich, 8093 Zurich, Switzerland},
  Art_number               = {6327046},
  Document_type            = {Conference Paper},
  Journal                  = {2012 Conference on Lasers and Electro-Optics, CLEO 2012},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84870318677&partnerID=40&md5=991fc6f3ca22832b3f52dc91ade0da39}
}

We report the measurement of high harmonics from oriented molecules in the gas phase. We show that attosecond and re-collision science provides a detailed and sensitive probe of electronic asymmetry in polar molecules. © 2012 OSA.

@Article{Heshami2012,
  Title                    = {Controllable-dipole quantum memory},
  Author                   = {Heshami, K.a , Green, A.a , Han, Y.a b , Rispe, A.a , Saglamyurek, E.a , Sinclair, N.a , Tittel, W.a , Simon, C.a },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2012},
  Number                   = {1},
  Volume                   = {86},

  Abstract                 = {We present a quantum memory protocol for photons that is based on the direct control of the transition dipole moment. We focus on the case where the light-matter interaction is enhanced by a cavity. We show that the optimal write process (maximizing the storage efficiency) is related to the optimal read process by a reversal of the effective time τ=dtg2(t)/κ, where g(t) is the time-dependent coupling and κ is the cavity decay rate. We discuss the implementation of the protocol in a rare-earth-ion-doped crystal where an optical transition can be turned on and off by switching a magnetic field. © 2012 American Physical Society.},
  Affiliation              = {Institute for Quantum Information Science, Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4, Canada; College of Science, National University of Defense Technology, Changsha 410073, China},
  Art_number               = {013813},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.86.013813},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84863700203&partnerID=40&md5=a59ca284041341168bd643ce6a7204bd}
}

We present a quantum memory protocol for photons that is based on the direct control of the transition dipole moment. We focus on the case where the light-matter interaction is enhanced by a cavity. We show that the optimal write process (maximizing the storage efficiency) is related to the optimal read process by a reversal of the effective time τ=dtg2(t)/κ, where g(t) is the time-dependent coupling and κ is the cavity decay rate. We discuss the implementation of the protocol in a rare-earth-ion-doped crystal where an optical transition can be turned on and off by switching a magnetic field. © 2012 American Physical Society.

@Article{Lee2012,
  Title                    = {Macroscopic non-classical states and terahertz quantum processing in room-temperature diamond},
  Author                   = {Lee, K.C.a , Sussman, B.J.b , Sprague, M.R.a , Michelberger, P.a , Reim, K.F.a , Nunn, J.a , Langford, N.K.a , Bustard, P.J.a b , Jaksch, D.a c , Walmsley, I.A.a },
  Journal                  = {Nature Photonics},
  Year                     = {2012},
  Number                   = {1},
  Pages                    = {41-44},
  Volume                   = {6},

  Abstract                 = {The nature of the transition between the familiar classical, macroscopic world and the quantum, microscopic one continues to be poorly understood. Expanding the regime of observable quantum behaviour to large-scale objects is therefore an exciting open problem. In macroscopic systems of interacting particles, rapid thermalization usually destroys any quantum coherence before it can be measured or used at room temperature. Here, we demonstrate quantum processing in the vibrational modes of a macroscopic diamond sample under ambient conditions. Using ultrafast Raman scattering, we create an extended, highly non-classical state in the optical phonon modes of bulk diamond. Direct measurement of phonon coherence and correlations establishes the non-classical nature of the crystal dynamics. These results show that optical phonons in diamond provide a unique opportunity for the study of large-scale quantum behaviour, and highlight the potential for diamond as a micro-photonic quantum processor capable of operating at terahertz rates.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; Centre for Quantum Technologies, National University of Singapore, Singapore, Singapore},
  Document_type            = {Article},
  Doi                      = {10.1038/nphoton.2011.296},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84255212119&partnerID=40&md5=79f1316d8f34c6f4cbd5d975f66fca83}
}

The nature of the transition between the familiar classical, macroscopic world and the quantum, microscopic one continues to be poorly understood. Expanding the regime of observable quantum behaviour to large-scale objects is therefore an exciting open problem. In macroscopic systems of interacting particles, rapid thermalization usually destroys any quantum coherence before it can be measured or used at room temperature. Here, we demonstrate quantum processing in the vibrational modes of a macroscopic diamond sample under ambient conditions. Using ultrafast Raman scattering, we create an extended, highly non-classical state in the optical phonon modes of bulk diamond. Direct measurement of phonon coherence and correlations establishes the non-classical nature of the crystal dynamics. These results show that optical phonons in diamond provide a unique opportunity for the study of large-scale quantum behaviour, and highlight the potential for diamond as a micro-photonic quantum processor capable of operating at terahertz rates.

@Article{Livingstone2012,
  Title                    = {Time-resolved photoelectron imaging of excited state relaxation dynamics in phenol, catechol, resorcinol, and hydroquinone},
  Author                   = {Livingstone, R.A.a , Thompson, J.O.F.a , Iljina, M.b , Donaldson, R.J.a , Sussman, B.J.c , Paterson, M.J.b , Townsend, D.a },
  Journal                  = {Journal of Chemical Physics},
  Year                     = {2012},
  Number                   = {18},
  Volume                   = {137},

  Abstract                 = {Time-resolved photoelectron imaging was used to investigate the dynamical evolution of the initially prepared S1 (ππ) excited state of phenol (hydroxybenzene), catechol (1,2-dihydroxybenzene), resorcinol (1,3-dihydroxybenzene), and hydroquinone (1,4-dihydroxybenzene) following excitation at 267 nm. Our analysis was supported by ab initio calculations at the coupled-cluster and CASSCF levels of theory. In all cases, we observe rapid (1 ps) intramolecular vibrational redistribution on the S1 potential surface. In catechol, the overall S1 state lifetime was observed to be 12.1 ps, which is 1-2 orders of magnitude shorter than in the other three molecules studied. This may be attributed to differences in the H atom tunnelling rate under the barrier formed by a conical intersection between the S1 state and the close lying S2 (πσ) state, which is dissociative along the O-H stretching coordinate. Further evidence of this S1S2 interaction is also seen in the time-dependent anisotropy of the photoelectron angular distributions we have observed. Our data analysis was assisted by a matrix inversion method for processing photoelectron images that is significantly faster than most other previously reported approaches and is extremely quick and easy to implement. © 2012 American Institute of Physics.},
  Affiliation              = {Institute of Photonics Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom; Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {184304},
  Document_type            = {Article},
  Doi                      = {10.1063/1.4765104},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84876479376&partnerID=40&md5=0e487aff882572f68309650e8f14effb}
}

Time-resolved photoelectron imaging was used to investigate the dynamical evolution of the initially prepared S1 (ππ) excited state of phenol (hydroxybenzene), catechol (1,2-dihydroxybenzene), resorcinol (1,3-dihydroxybenzene), and hydroquinone (1,4-dihydroxybenzene) following excitation at 267 nm. Our analysis was supported by ab initio calculations at the coupled-cluster and CASSCF levels of theory. In all cases, we observe rapid (1 ps) intramolecular vibrational redistribution on the S1 potential surface. In catechol, the overall S1 state lifetime was observed to be 12.1 ps, which is 1-2 orders of magnitude shorter than in the other three molecules studied. This may be attributed to differences in the H atom tunnelling rate under the barrier formed by a conical intersection between the S1 state and the close lying S2 (πσ) state, which is dissociative along the O-H stretching coordinate. Further evidence of this S1S2 interaction is also seen in the time-dependent anisotropy of the photoelectron angular distributions we have observed. Our data analysis was assisted by a matrix inversion method for processing photoelectron images that is significantly faster than most other previously reported approaches and is extremely quick and easy to implement. © 2012 American Institute of Physics.

@Conference{Nunn2012c,
  Title                    = {Synchronizing single photons with quantum memories},
  Author                   = {Nunn, J., Langford, N.K., Champion, T., Sprague, M.R., Michelberger, P.S., Ka Lee, C., Jin, X.-M., England, D., Kolthammer, W.S., Walmsley, I.A.},
  Year                     = {2012},
  Pages                    = {JW3I.2},

  Abstract                 = {Without deterministic single photon sources, multiphoton rates fall exponentially with the number of photons required, making practical photonics unfeasible. We show how quantum memories improve multiphoton rates by many orders of magnitude. © 2011 Optical Society of America.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU, United Kingdom},
  Document_type            = {Conference Paper},
  Journal                  = {CLEO: Science and Innovations, CLEO_SI 2012},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84890690233&partnerID=40&md5=f37e4d2b37705ed4538a965f5f37e552}
}

Without deterministic single photon sources, multiphoton rates fall exponentially with the number of photons required, making practical photonics unfeasible. We show how quantum memories improve multiphoton rates by many orders of magnitude. © 2011 Optical Society of America.

@Article{Reim2012a,
  Title                    = {Multipulse addressing of a Raman quantum memory: Configurable beam splitting and efficient readout},
  Author                   = {Reim, K.F.a b , Nunn, J.a , Jin, X.-M.a c , Michelberger, P.S.a , Champion, T.F.M.a , England, D.G.a , Lee, K.C.a , Kolthammer, W.S.a , Langford, N.K.a d , Walmsley, I.A.a },
  Journal                  = {Physical Review Letters},
  Year                     = {2012},
  Number                   = {26},
  Volume                   = {108},

  Abstract                 = {Quantum memories are vital to the scalability of photonic quantum information processing (PQIP), since the storage of photons enables repeat-until-success strategies. On the other hand, the key element of all PQIP architectures is the beam splitter, which allows us to coherently couple optical modes. Here, we show how to combine these crucial functionalities by addressing a Raman quantum memory with multiple control pulses. The result is a coherent optical storage device with an extremely large time bandwidth product, that functions as an array of dynamically configurable beam splitters, and that can be read out with arbitrarily high efficiency. Networks of such devices would allow fully scalable PQIP, with applications in quantum computation, long distance quantum communications and quantum metrology. © 2012 American Physical Society.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom; Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland; Centre for Quantum Technologies, National University of Singapore, 117543 Singapore, Singapore; Department of Physics, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom},
  Art_number               = {263602},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.108.263602},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84863002085&partnerID=40&md5=2036b5173c1552ce10eca2c7911864f7}
}

Quantum memories are vital to the scalability of photonic quantum information processing (PQIP), since the storage of photons enables repeat-until-success strategies. On the other hand, the key element of all PQIP architectures is the beam splitter, which allows us to coherently couple optical modes. Here, we show how to combine these crucial functionalities by addressing a Raman quantum memory with multiple control pulses. The result is a coherent optical storage device with an extremely large time bandwidth product, that functions as an array of dynamically configurable beam splitters, and that can be read out with arbitrarily high efficiency. Networks of such devices would allow fully scalable PQIP, with applications in quantum computation, long distance quantum communications and quantum metrology. © 2012 American Physical Society.

@Conference{Reim2012,
  Title                    = {Multi-pulse addressing of a Raman quantum memory: Configurable beam splitting and efficient readout},
  Author                   = {Reim, K.F.a b , Nunn, J.a , Jin, X.-M.a c , Michelberger, P.S.a , Champion, T.F.M.a , England, D.G.a , Lee, K.C.a , Langford, N.K.a d , Walmsley, I.A.a },
  Year                     = {2012},

  Abstract                 = {We address an optical quantum memory with multiple pulses, enabling unit efficiency readout and programmable beam splitting. The resulting coherent processor with built-in storage is universal for scalable photonic quantum information processing. © 2012 OSA.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom; Department of Physics, ETH Zürich, CH-8093 Zürich, Switzerland; Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore; Department of Physics, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom},
  Art_number               = {6327035},
  Document_type            = {Conference Paper},
  Journal                  = {2012 Conference on Lasers and Electro-Optics, CLEO 2012},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84870315515&partnerID=40&md5=6adb63544278ce07da116cad58059d9f}
}

We address an optical quantum memory with multiple pulses, enabling unit efficiency readout and programmable beam splitting. The resulting coherent processor with built-in storage is universal for scalable photonic quantum information processing. © 2012 OSA.

@Conference{Sprague2012,
  Title                    = {Entangling the motion of diamonds at room temperature},
  Author                   = {Sprague, M.R.a , Lee, K.C.a , Sussman, B.J.b , Nunn, J.a , Langford, N.K.a , Jin, X.-M.a c , Champion, T.a , Michelberger, P.a , Reim, K.F.a , England, D.a , Jaksch, D.a c , Walmsley, I.A.a },
  Year                     = {2012},

  Abstract                 = {We demonstrate entanglement between the vibrational mode of two macroscopic, spatially-separated diamonds at room temperature with ultrashort pulses and a far-off-resonant Raman interaction. © 2012 Optical Society of America.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Rd, Oxford OX1 3P4, United Kingdom; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; Centre for Quantum Technologies, National University of Singapore, Singapore},
  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84893496237&partnerID=40&md5=f1b63fbe711ee12547e2dd78b9b08a7d}
}

We demonstrate entanglement between the vibrational mode of two macroscopic, spatially-separated diamonds at room temperature with ultrashort pulses and a far-off-resonant Raman interaction. © 2012 Optical Society of America.

@Article{Weeraman2012,
  Title                    = {A combined vibrational sum frequency generation spectroscopy and atomic force microscopy study of sphingomyelin-cholesterol monolayers},
  Author                   = {Weeraman, C., Chen, M., Moffatt, D.J., Lausten, R., Stolow, A., Johnston, L.J.},
  Journal                  = {Langmuir},
  Year                     = {2012},
  Number                   = {36},
  Pages                    = {12999-13007},
  Volume                   = {28},

  Abstract                 = {A combination of vibrational sum frequency generation spectroscopy and atomic force microscopy is used to study the changes in morphology and conformational order in monolayers prepared from three natural sphingomyelin (SM) mixtures as a function of surface pressure and cholesterol concentration. The most homogeneous SM gave monolayers with well-ordered acyl chains and few gauche defects with relatively small effects of either increasing surface pressure or cholesterol addition. Heterogeneous SM mixtures with a mixture of acyl chain lengths or with significant fractions of unsaturated acyl chains had much larger contributions from gauche defects at low surface pressure and gave increasingly well-ordered monolayers as the surface pressure increased. They also showed substantial increases in lipid chain order after cholesterol addition. Overall, these results are consistent with the strong hydrogen bonding capacity of SM leading to well-ordered monolayers over a range of surface pressures. The changes in acyl chain order for natural SMs as a function of cholesterol are relevant to formation of sphingolipid-cholesterol enriched domains in cell membranes. © Published 2012 by the American Chemical Society.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada},
  Document_type            = {Article},
  Doi                      = {10.1021/la301332e},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84866110546&partnerID=40&md5=33b3ce6e796d7d43e6642dd7888fb9e3}
}

A combination of vibrational sum frequency generation spectroscopy and atomic force microscopy is used to study the changes in morphology and conformational order in monolayers prepared from three natural sphingomyelin (SM) mixtures as a function of surface pressure and cholesterol concentration. The most homogeneous SM gave monolayers with well-ordered acyl chains and few gauche defects with relatively small effects of either increasing surface pressure or cholesterol addition. Heterogeneous SM mixtures with a mixture of acyl chain lengths or with significant fractions of unsaturated acyl chains had much larger contributions from gauche defects at low surface pressure and gave increasingly well-ordered monolayers as the surface pressure increased. They also showed substantial increases in lipid chain order after cholesterol addition. Overall, these results are consistent with the strong hydrogen bonding capacity of SM leading to well-ordered monolayers over a range of surface pressures. The changes in acyl chain order for natural SMs as a function of cholesterol are relevant to formation of sphingolipid-cholesterol enriched domains in cell membranes. © Published 2012 by the American Chemical Society.

@Conference{Bustard2011,
  Title                    = {From molecular control to quantum technology with the dynamic stark effect},
  Author                   = {Bustard, P.J., Sussman, B.J.},
  Year                     = {2011},

  Abstract                 = {The application of nonresonant lasers to quantum systems can modify energy levels in a general way. This approach, using the nonresonant dynamic Stark effect, is an effective mechanism for modifying chemical dynamics. These molecular techniques have analogous implementations in quantum technologies. Applications include controlling vacuum fluctuations to create molecular alignment and broadband light sources, photonic catalysis, quantum memories in atomic vapours, and photonics in bulk diamond phonons. The links between these different applications are investigated. © 2011 IEEE.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {5953734},
  Document_type            = {Conference Paper},
  Doi                      = {10.1109/ICO-IP.2011.5953734},
  Journal                  = {2011 ICO International Conference on Information Photonics, IP 2011},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-80051746272&partnerID=40&md5=00f4e99f02f8295abbd8d4524583769e}
}

The application of nonresonant lasers to quantum systems can modify energy levels in a general way. This approach, using the nonresonant dynamic Stark effect, is an effective mechanism for modifying chemical dynamics. These molecular techniques have analogous implementations in quantum technologies. Applications include controlling vacuum fluctuations to create molecular alignment and broadband light sources, photonic catalysis, quantum memories in atomic vapours, and photonics in bulk diamond phonons. The links between these different applications are investigated. © 2011 IEEE.

@Article{Bustard2011b,
  Title                    = {Quantum random bit generation using stimulated Raman scattering},
  Author                   = {Bustard, P.J.a b , Moffatt, D.b , Lausten, R.b , Wu, G.b , Walmsley, I.A.a , Sussman, B.J.b },
  Journal                  = {Optics Express},
  Year                     = {2011},
  Number                   = {25},
  Pages                    = {25173-25180},
  Volume                   = {19},

  Abstract                 = {Random number sequences are a critical resource in a wide variety of information systems, including applications in cryptography, simulation, and data sampling. We introduce a quantum random number generator based on the phase measurement of Stokes light generated by amplification of zero-point vacuum fluctuations using stimulated Raman scattering. This is an example of quantum noise amplification using the most noise-free process possible: near unitary quantum evolution. The use of phase offers robustness to classical pump noise and the ability to generate multiple bits per measurement. The Stokes light is generated with high intensity and as a result, fast detectors with high signal-to-noise ratios can be used for measurement, eliminating the need for single-photon sensitive devices. The demonstrated implementation uses optical phonons in bulk diamond. © 2011 Optical Society of America.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom; Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Document_type            = {Article},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-82955208417&partnerID=40&md5=218eb51fdf539a5f42579a1849fd28a1}
}

Random number sequences are a critical resource in a wide variety of information systems, including applications in cryptography, simulation, and data sampling. We introduce a quantum random number generator based on the phase measurement of Stokes light generated by amplification of zero-point vacuum fluctuations using stimulated Raman scattering. This is an example of quantum noise amplification using the most noise-free process possible: near unitary quantum evolution. The use of phase offers robustness to classical pump noise and the ability to generate multiple bits per measurement. The Stokes light is generated with high intensity and as a result, fast detectors with high signal-to-noise ratios can be used for measurement, eliminating the need for single-photon sensitive devices. The demonstrated implementation uses optical phonons in bulk diamond. © 2011 Optical Society of America.

@Article{Bustard2011a,
  Title                    = {From molecular control to quantum technology with the dynamic Stark effect},
  Author                   = {Bustard, P.J.a b , Wu, G.a , Lausten, R.a , Townsend, D.c , Walmsley, I.A.b , Stolow, A.a , Sussman, B.J.a },
  Journal                  = {Faraday Discussions},
  Year                     = {2011},
  Pages                    = {321-342},
  Volume                   = {153},

  Abstract                 = {The non-resonant dynamic Stark effect is a powerful and general way of manipulating ultrafast processes in atoms, molecules, and solids with exquisite precision. We discuss the physics behind this effect, and demonstrate its efficacy as a method of control in a variety of systems. These applications range from the control of molecular rotational dynamics to the manipulation of chemical reaction dynamics, and from the suppression of vacuum fluctuation effects in coherent preparation of matter, to the dynamic generation of bandwidth for storage of broadband quantum states of light. © 2011 The Royal Society of Chemistry.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada; Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom; School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom},
  Document_type            = {Article},
  Doi                      = {10.1039/c1fd00067e},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-80054984623&partnerID=40&md5=2efcafa7ebd4ae7cc0f074b2e96bc529}
}

The non-resonant dynamic Stark effect is a powerful and general way of manipulating ultrafast processes in atoms, molecules, and solids with exquisite precision. We discuss the physics behind this effect, and demonstrate its efficacy as a method of control in a variety of systems. These applications range from the control of molecular rotational dynamics to the manipulation of chemical reaction dynamics, and from the suppression of vacuum fluctuation effects in coherent preparation of matter, to the dynamic generation of bandwidth for storage of broadband quantum states of light. © 2011 The Royal Society of Chemistry.

@Conference{Han2011,
  Title                    = {Controllable-dipole quantum memory},
  Author                   = {Han, Y.a b , Heshami, K.a , Rispe, A.a c , Saglamyurek, E.a , Sinclair, N.a , Li, C.-Z.b , Tittel, W.a , Simon, C.a },
  Year                     = {2011},

  Abstract                 = {To build quantum memories for light with atomic ensembles one needs to map single photons into atomic excitations and freeze them until releasing them back as photons on demand. Here we present an idea for realizing this storage-recall procedure by directly controlling the transition dipole moment in a two-level atomic ensemble. An analytical treatment of the problem is performed, and the physical requirements on the proposed scheme are discussed. We propose an implementation employing a magneto-dependent transition dipole moment in a Tm3+:YAG crystal. © OSA/ICQI 2011.},
  Affiliation              = {Institute for Quantum Information Science, Department of Physics and Astronomy, University of Calgary, Calgary T2N 1N4, AL, Canada; College of Science, National University of Defense Technology, Changsha 410073, Canada; École normale supérieure, Paris, France},
  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84893623118&partnerID=40&md5=fd58b6e0f36c3bba0e81a72c833bcc19}
}

To build quantum memories for light with atomic ensembles one needs to map single photons into atomic excitations and freeze them until releasing them back as photons on demand. Here we present an idea for realizing this storage-recall procedure by directly controlling the transition dipole moment in a two-level atomic ensemble. An analytical treatment of the problem is performed, and the physical requirements on the proposed scheme are discussed. We propose an implementation employing a magneto-dependent transition dipole moment in a Tm3+:YAG crystal. © OSA/ICQI 2011.

@Conference{Heshami2011,
  Title                    = {Precision requirements for spin-echo based quantum memories},
  Author                   = {Heshami, K.a , Sangouard, N.b , Minar, J.b , De Riedmatten, H.c d , Simon, C.a },
  Year                     = {2011},

  Abstract                 = {Spin echo techniques are essential for achieving long coherence times in solid state quantum memories for light because of inhomogeneous broadening of the spin transitions. Here we study the effects of radio frequency decoherence control pulse imperfections in detail, using both a semi-classical and a fully quantummechanical approach. Our results show that high efficiencies and low noise-to-signal ratios can be achieved for the quantum memories in the single-photon regime for realistic levels of control pulse precision. We also analyze errors due to imperfect initial state preparation (optical pumping), showing that they are likely to be more important than control pulse errors in many practical circumstances. These results are crucial for future developments of solid state quantum memories. © OSA/ICQI 2011.},
  Affiliation              = {Institute for Quantum Information Science, Department of Physics and Astronomy, University of Calgary, Calgary T2N 1N4, AB, Canada; Group of Applied Physics, University of Geneva, Switzerland; ICFO-Institute of Photonic Sciences, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain; ICREA-Instituci'o Catalana de Recerca i Estudis Avançats, 08015 Barcelona, Spain},
  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84893570870&partnerID=40&md5=a7abdfb0bccf3cd4d19329808490b839}
}

Spin echo techniques are essential for achieving long coherence times in solid state quantum memories for light because of inhomogeneous broadening of the spin transitions. Here we study the effects of radio frequency decoherence control pulse imperfections in detail, using both a semi-classical and a fully quantummechanical approach. Our results show that high efficiencies and low noise-to-signal ratios can be achieved for the quantum memories in the single-photon regime for realistic levels of control pulse precision. We also analyze errors due to imperfect initial state preparation (optical pumping), showing that they are likely to be more important than control pulse errors in many practical circumstances. These results are crucial for future developments of solid state quantum memories. © OSA/ICQI 2011.

@Article{Heshami2011a,
  Title                    = {Precision requirements for spin-echo-based quantum memories},
  Author                   = {Heshami, K.a , Sangouard, N.b , Minár, J.b , De Riedmatten, H.c d , Simon, C.a },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2011},
  Number                   = {3},
  Volume                   = {83},

  Abstract                 = {Spin-echo techniques are essential for achieving long coherence times in solid-state quantum memories for light because of inhomogeneous broadening of the spin transitions. It has been suggested that unrealistic levels of precision for the radio-frequency control pulses would be necessary for successful decoherence control at the quantum level. Here we study the effects of pulse imperfections in detail, using both a semiclassical and a fully quantum-mechanical approach. Our results show that high efficiencies and low noise-to-signal ratios can be achieved for the quantum memories in the single-photon regime for realistic levels of control pulse precision. We also analyze errors due to imperfect initial-state preparation (optical pumping), showing that they are likely to be more important than control pulse errors in many practical circumstances. These results are crucial for future developments of solid-state quantum memories. © 2011 American Physical Society.},
  Affiliation              = {Institute for Quantum Information Science, Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4, Canada; Group of Applied Physics, University of Geneva, CH-1211 Geneva, Switzerland; ICFO-Institute of Photonic Sciences, Mediterranean Technology Park, ES-08860 Castelldefels (Barcelona), Spain; ICREA-Institució Catalana de Recerca i Estudis Avançats, ES-08015 Barcelona, Spain},
  Art_number               = {032315},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.83.032315},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79952907548&partnerID=40&md5=9693ea5c21326e50f27133bdf5f1f840}
}

Spin-echo techniques are essential for achieving long coherence times in solid-state quantum memories for light because of inhomogeneous broadening of the spin transitions. It has been suggested that unrealistic levels of precision for the radio-frequency control pulses would be necessary for successful decoherence control at the quantum level. Here we study the effects of pulse imperfections in detail, using both a semiclassical and a fully quantum-mechanical approach. Our results show that high efficiencies and low noise-to-signal ratios can be achieved for the quantum memories in the single-photon regime for realistic levels of control pulse precision. We also analyze errors due to imperfect initial-state preparation (optical pumping), showing that they are likely to be more important than control pulse errors in many practical circumstances. These results are crucial for future developments of solid-state quantum memories. © 2011 American Physical Society.

@Article{Hockett2011,
  Title                    = {Time-resolved imaging of purely valence-electron dynamics during a chemical reaction},
  Author                   = {Hockett, P.a , Bisgaard, C.Z.a b , Clarkin, O.J.c , Stolow, A.a c },
  Journal                  = {Nature Physics},
  Year                     = {2011},
  Number                   = {8},
  Pages                    = {612-615},
  Volume                   = {7},

  Abstract                 = {Chemical reactions are manifestations of the dynamics of molecular valence electrons and their couplings to atomic motions. Emerging methods in attosecond science can probe purely electronic dynamics in atomic and molecular systems 1-6. By contrast, time-resolved structural-dynamics methods such as electron 7-10 or X-ray diffraction 11 and X-ray absorption 12 yield complementary information about the atomic motions. Time-resolved methods that are directly sensitive to both valence-electron dynamics and atomic motions include photoelectron spectroscopy and high-harmonic generation: in both cases, this sensitivity derives from the ionization-matrix element 18,19. Here we demonstrate a time-resolved molecular-frame photoelectron-angular-distribution (TRMFPAD) method for imaging the purely valence-electron dynamics during a chemical reaction. Specifically, the TRMFPADs measured during the non-adiabatic photodissociation of carbon disulphide demonstrate how the purely electronic rearrangements of the valence electrons can be projected from inherently coupled electronic-vibrational dynamics. Combined with ongoing efforts in molecular frame alignment 20 and orientation 21,22, TRMFPADs offer the promise of directly imaging valence-electron dynamics during molecular processes without involving the use of strong, highly perturbing laser fields 23. © 2011 Macmillan Publishers Limited. All rights reserved.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada; Department of Chemistry, University of Copenhagen, Copenhagen DK-2100, Denmark; Department of Chemistry, Queens University, Kingston, ON K7L 3N6, Canada},
  Document_type            = {Article},
  Doi                      = {10.1038/nphys1980},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79961022680&partnerID=40&md5=0f1afe659e9300a3a4ba028b45c295db}
}

Chemical reactions are manifestations of the dynamics of molecular valence electrons and their couplings to atomic motions. Emerging methods in attosecond science can probe purely electronic dynamics in atomic and molecular systems 1-6. By contrast, time-resolved structural-dynamics methods such as electron 7-10 or X-ray diffraction 11 and X-ray absorption 12 yield complementary information about the atomic motions. Time-resolved methods that are directly sensitive to both valence-electron dynamics and atomic motions include photoelectron spectroscopy and high-harmonic generation: in both cases, this sensitivity derives from the ionization-matrix element 18,19. Here we demonstrate a time-resolved molecular-frame photoelectron-angular-distribution (TRMFPAD) method for imaging the purely valence-electron dynamics during a chemical reaction. Specifically, the TRMFPADs measured during the non-adiabatic photodissociation of carbon disulphide demonstrate how the purely electronic rearrangements of the valence electrons can be projected from inherently coupled electronic-vibrational dynamics. Combined with ongoing efforts in molecular frame alignment 20 and orientation 21,22, TRMFPADs offer the promise of directly imaging valence-electron dynamics during molecular processes without involving the use of strong, highly perturbing laser fields 23. © 2011 Macmillan Publishers Limited. All rights reserved.

@Article{Lee2011,
  Title                    = {Entangling macroscopic diamonds at room temperature},
  Author                   = {Lee, K.C.a , Sprague, M.R.a , Sussman, B.J.b , Nunn, J.a , Langford, N.K.a , Jin, X.-M.a c , Champion, T.a , Michelberger, P.a , Reim, K.F.a , England, D.a , Jaksch, D.a c , Walmsley, I.A.a },
  Journal                  = {Science},
  Year                     = {2011},
  Number                   = {6060},
  Pages                    = {1253-1256},
  Volume                   = {334},

  Abstract                 = {Quantum entanglement in the motion of macroscopic solid bodies has implications both for quantum technologies and foundational studies of the boundary between the quantum and classical worlds. Entanglement is usually fragile in room-temperature solids, owing to strong interactions both internally and with the noisy environment. We generated motional entanglement between vibrational states of two spatially separated, millimeter-sized diamonds at room temperature. By measuring strong nonclassical correlations between Raman-scattered photons, we showed that the quantum state of the diamonds has positive concurrence with 98% probability. Our results show that entanglement can persist in the classical context of moving macroscopic solids in ambient conditions.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; Centre for Quantum Technologies, National University of Singapore, Singapore},
  Document_type            = {Article},
  Doi                      = {10.1126/science.1211914},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-82755187063&partnerID=40&md5=1ec02866ac515c76758d960ab1c80651}
}

Quantum entanglement in the motion of macroscopic solid bodies has implications both for quantum technologies and foundational studies of the boundary between the quantum and classical worlds. Entanglement is usually fragile in room-temperature solids, owing to strong interactions both internally and with the noisy environment. We generated motional entanglement between vibrational states of two spatially separated, millimeter-sized diamonds at room temperature. By measuring strong nonclassical correlations between Raman-scattered photons, we showed that the quantum state of the diamonds has positive concurrence with 98% probability. Our results show that entanglement can persist in the classical context of moving macroscopic solids in ambient conditions.

@Article{Martay2011,
  Title                    = {Extending electron orbital precession to the molecular case: Use of orbital alignment for observation of wavepacket dynamics},
  Author                   = {Martay, H.E.L., England, D.G., McCabe, D.J., Walmsley, I.A.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2011},
  Number                   = {4},
  Volume                   = {83},

  Abstract                 = {The complexity of ultrafast molecular photoionization presents an obstacle to the modeling of pump-probe experiments. Here, a simple optimized model of atomic rubidium is combined with a molecular dynamics model to predict quantitatively the results of a pump-probe experiment in which long-range rubidium dimers are first excited, then ionized after a variable delay. The method is illustrated by the outline of two proposed feasible experiments and the calculation of their outcomes. Both of these proposals use Feshbach Rb872 molecules. We show that long-range molecular pump-probe experiments should observe spin-orbit precession given a suitable pump pulse, and that the associated high-frequency beat signal in the ionization probability decays after a few tens of picoseconds. If the molecule was to be excited to only a single fine-structure state, then a low-frequency oscillation in the internuclear separation would be detectable through the time-dependent ionization cross section, giving a mechanism that would enable observation of coherent vibrational motion in this molecule. © 2011 American Physical Society.},
  Affiliation              = {Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, OX1 3PU, United Kingdom},
  Art_number               = {043419},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.83.043419},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79960623436&partnerID=40&md5=c6727115fafa142ef551ba179ae35c0d}
}

The complexity of ultrafast molecular photoionization presents an obstacle to the modeling of pump-probe experiments. Here, a simple optimized model of atomic rubidium is combined with a molecular dynamics model to predict quantitatively the results of a pump-probe experiment in which long-range rubidium dimers are first excited, then ionized after a variable delay. The method is illustrated by the outline of two proposed feasible experiments and the calculation of their outcomes. Both of these proposals use Feshbach Rb872 molecules. We show that long-range molecular pump-probe experiments should observe spin-orbit precession given a suitable pump pulse, and that the associated high-frequency beat signal in the ionization probability decays after a few tens of picoseconds. If the molecule was to be excited to only a single fine-structure state, then a low-frequency oscillation in the internuclear separation would be detectable through the time-dependent ionization cross section, giving a mechanism that would enable observation of coherent vibrational motion in this molecule. © 2011 American Physical Society.

@Article{Schalk2011,
  Title                    = {Rotational dephasing of symmetric top molecules: Analytic expressions and applications},
  Author                   = {Schalk, O.a b , Hockett, P.a },
  Journal                  = {Chemical Physics Letters},
  Year                     = {2011},
  Number                   = {4-6},
  Pages                    = {237-241},
  Volume                   = {517},

  Abstract                 = {An analytic expression for the rotational dephasing of an ensemble of symmetric top molecules excited by a short laser pulse is developed. This expression can be used to discern rotation from electronic and vibrational dynamics in polarization resolved studies and is computationally less demanding than numeric simulations used previously. The result agrees well with quantum mechanical treatment, both at room temperature and at cold rotational temperatures found in molecular beams. Applications to transient anisotropy and photoelectron angular distributions are given. Finally, we raise the possibility of combining transient anisotropy techniques with time-resolved photoelectron spectroscopy. © 2011 Elsevier B.V. All rights reserved.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada; Lehrstuhl für BioMolekulare Optik, Ludwig-Maximilians-Universität (LMU), Oettingenstraße 67, 80538 München, Germany},
  Document_type            = {Article},
  Doi                      = {10.1016/j.cplett.2011.10.046},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-82455210802&partnerID=40&md5=f2dc8c92032dbf64414b1b96850f29b0}
}

An analytic expression for the rotational dephasing of an ensemble of symmetric top molecules excited by a short laser pulse is developed. This expression can be used to discern rotation from electronic and vibrational dynamics in polarization resolved studies and is computationally less demanding than numeric simulations used previously. The result agrees well with quantum mechanical treatment, both at room temperature and at cold rotational temperatures found in molecular beams. Applications to transient anisotropy and photoelectron angular distributions are given. Finally, we raise the possibility of combining transient anisotropy techniques with time-resolved photoelectron spectroscopy. © 2011 Elsevier B.V. All rights reserved.

@Article{Sussman2011,
  Title                    = {Five ways to the nonresonant dynamic Stark effect},
  Author                   = {Sussman, B.J.},
  Journal                  = {American Journal of Physics},
  Year                     = {2011},
  Number                   = {5},
  Pages                    = {477-484},
  Volume                   = {79},

  Abstract                 = {The dynamic Stark effect is the quasistatic shift in energy levels due to the application of optical fields. The effect is in many ways similar to the static Stark effect. However, the dynamic Stark effect can be applied on rapid time scales and with high energies, comparable to those of atoms and molecules themselves. The dynamic Stark effect due to nonresonant laser fields is used in a myriad of contemporary experiments to hold and align molecules, to shape potential energy surfaces, and to make rapid transient birefringence. Five approaches of increasing sophistication are used to describe the dynamic Stark effect. One application, molecular alignment, is summarized and a comparison is made between the dynamic Stark effect and Stokes light generation in a Raman scattering process. © 2011 American Association of Physics Teachers.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Document_type            = {Article},
  Doi                      = {10.1119/1.3553018},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79954538943&partnerID=40&md5=3a2a2ba40815bba32a3a5216352dd36e}
}

The dynamic Stark effect is the quasistatic shift in energy levels due to the application of optical fields. The effect is in many ways similar to the static Stark effect. However, the dynamic Stark effect can be applied on rapid time scales and with high energies, comparable to those of atoms and molecules themselves. The dynamic Stark effect due to nonresonant laser fields is used in a myriad of contemporary experiments to hold and align molecules, to shape potential energy surfaces, and to make rapid transient birefringence. Five approaches of increasing sophistication are used to describe the dynamic Stark effect. One application, molecular alignment, is summarized and a comparison is made between the dynamic Stark effect and Stokes light generation in a Raman scattering process. © 2011 American Association of Physics Teachers.

@Article{Townsend2011,
  Title                    = {A Stark future for quantum control},
  Author                   = {Townsend, D.a , Sussman, B.J.b , Stolow, A.b },
  Journal                  = {Journal of Physical Chemistry A},
  Year                     = {2011},
  Number                   = {4},
  Pages                    = {357-373},
  Volume                   = {115},

  Abstract                 = {We present an overview of developments using the nonresonant dynamic Stark effect within the fields of time-resolved molecular dynamics and quantum control, drawing on examples from our own recent work. Particular emphasis is placed on the notion that "dynamics" and "control" are not distinct disciplines and that a clear synergy exits between these areas which has, up to now, been somewhat underexploited. The dynamic Stark effect is a universal interaction which we expect to have broad applicability. © 2011 American Chemical Society.},
  Affiliation              = {School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom; Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Document_type            = {Review},
  Doi                      = {10.1021/jp109095d},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79851481326&partnerID=40&md5=abe4207119c1c0d2bdc2797d5ba32c05}
}

We present an overview of developments using the nonresonant dynamic Stark effect within the fields of time-resolved molecular dynamics and quantum control, drawing on examples from our own recent work. Particular emphasis is placed on the notion that "dynamics" and "control" are not distinct disciplines and that a clear synergy exits between these areas which has, up to now, been somewhat underexploited. The dynamic Stark effect is a universal interaction which we expect to have broad applicability. © 2011 American Chemical Society.

@Article{Wu2011,
  Title                    = {Time-resolved photoelectron spectroscopy: From wavepackets to observables},
  Author                   = {Wu, G.a , Hockett, P.a , Stolow, A.a b },
  Journal                  = {Physical Chemistry Chemical Physics},
  Year                     = {2011},
  Number                   = {41},
  Pages                    = {18447-18467},
  Volume                   = {13},

  Abstract                 = {Time-resolved photoelectron spectroscopy (TRPES) is a powerful tool for the study of intramolecular dynamics, particularly excited state non-adiabatic dynamics in polyatomic molecules. Depending on the problem at hand, different levels of TRPES measurements can be performed: time-resolved photoelectron yield; time- and energy-resolved photoelectron yield; time-, energy-, and angle-resolved photoelectron yield. In this pedagogical overview, a conceptual framework for time-resolved photoionization measurements is presented, together with discussion of relevant theory for the different aspects of TRPES. Simple models are used to illustrate the theory, and key concepts are further amplified by experimental examples. These examples are chosen to show the application of TRPES to the investigation of a range of problems in the excited state dynamics of molecules: from the simplest vibrational wavepacket on a single potential energy surface; to disentangling intrinsically coupled electronic and nuclear motions; to identifying the electronic character of the intermediate states involved in non-adiabatic dynamics by angle-resolved measurements in the molecular frame, the most complete measurement. © 2011 the Owner Societies.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada; Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada},
  Document_type            = {Review},
  Doi                      = {10.1039/c1cp22031d},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-80054031035&partnerID=40&md5=c660cef292a49321bf585eaec24d6fd8}
}

Time-resolved photoelectron spectroscopy (TRPES) is a powerful tool for the study of intramolecular dynamics, particularly excited state non-adiabatic dynamics in polyatomic molecules. Depending on the problem at hand, different levels of TRPES measurements can be performed: time-resolved photoelectron yield; time- and energy-resolved photoelectron yield; time-, energy-, and angle-resolved photoelectron yield. In this pedagogical overview, a conceptual framework for time-resolved photoionization measurements is presented, together with discussion of relevant theory for the different aspects of TRPES. Simple models are used to illustrate the theory, and key concepts are further amplified by experimental examples. These examples are chosen to show the application of TRPES to the investigation of a range of problems in the excited state dynamics of molecules: from the simplest vibrational wavepacket on a single potential energy surface; to disentangling intrinsically coupled electronic and nuclear motions; to identifying the electronic character of the intermediate states involved in non-adiabatic dynamics by angle-resolved measurements in the molecular frame, the most complete measurement. © 2011 the Owner Societies.

@Article{Bustard2010,
  Title                    = {Amplification of impulsively excited molecular rotational coherence},
  Author                   = {Bustard, P.J.a , Sussman, B.J.a b , Walmsley, I.A.a },
  Journal                  = {Physical Review Letters},
  Year                     = {2010},
  Number                   = {19},
  Volume                   = {104},

  Abstract                 = {We propose a scheme for preparation of high-coherence molecular dynamics which are phase stable with respect to ultrashort pulses. We experimentally demonstrate an example of this scheme using a phase-independent, nanosecond-duration, pump pulse to prepare a rotational coherence in molecular hydrogen. This rotational coherence is made phase stable with respect to a separate source of ultrashort pulses by seeding. The coherence is used to generate spectral broadening of femtosecond probe radiation by molecular phase modulation. © 2010 The American Physical Society.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom; Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {193902},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.104.193902},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77952348703&partnerID=40&md5=cf38c215b512e2d300a97dfa7a5519ca}
}

We propose a scheme for preparation of high-coherence molecular dynamics which are phase stable with respect to ultrashort pulses. We experimentally demonstrate an example of this scheme using a phase-independent, nanosecond-duration, pump pulse to prepare a rotational coherence in molecular hydrogen. This rotational coherence is made phase stable with respect to a separate source of ultrashort pulses by seeding. The coherence is used to generate spectral broadening of femtosecond probe radiation by molecular phase modulation. © 2010 The American Physical Society.

@Article{Han2010,
  Title                    = {Quantum repeaters based on Rydberg-blockade-coupled atomic ensembles},
  Author                   = {Han, Y.a b , He, B.a , Heshami, K.a , Li, C.-Z.b , Simon, C.a },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2010},
  Number                   = {5},
  Volume                   = {81},

  Abstract                 = {We propose a scheme for realizing quantum repeaters with Rydberg-blockade-coupled atomic ensembles, based on a recently proposed collective encoding strategy. Rydberg-blockade-mediated two-qubit gates and efficient cooperative photon emission are employed to create ensemble-photon entanglement. Thanks to deterministic entanglement swapping operations via Rydberg-based two-qubit gates, and to the suppression of multiexcitation errors by the blockade effect, the entanglement distribution rate of the present scheme is higher by orders of magnitude than the rates achieved by other ensemble-based repeaters. We also show how to realize temporal multiplexing with this system, which offers an additional speedup in entanglement distribution. © 2010 The American Physical Society.},
  Affiliation              = {Institute for Quantum Information Science, Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4, Canada; College of Science, National University of Defense Technology, Changsha 410073, China},
  Art_number               = {052311},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.81.052311},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77952355124&partnerID=40&md5=255ac8cd27bf27c3c068255a644d2eef}
}

We propose a scheme for realizing quantum repeaters with Rydberg-blockade-coupled atomic ensembles, based on a recently proposed collective encoding strategy. Rydberg-blockade-mediated two-qubit gates and efficient cooperative photon emission are employed to create ensemble-photon entanglement. Thanks to deterministic entanglement swapping operations via Rydberg-based two-qubit gates, and to the suppression of multiexcitation errors by the blockade effect, the entanglement distribution rate of the present scheme is higher by orders of magnitude than the rates achieved by other ensemble-based repeaters. We also show how to realize temporal multiplexing with this system, which offers an additional speedup in entanglement distribution. © 2010 The American Physical Society.

@Article{Hockett2010,
  Title                    = {Photoelectron angular distributions from rotationally state-selected NH3(B1E″): Dependence on ion rotational state and polarization geometry},
  Author                   = {Hockett, P.a b , Staniforth, M.a , Reid, K.L.a },
  Journal                  = {Molecular Physics},
  Year                     = {2010},
  Number                   = {7-9},
  Pages                    = {1045-1054},
  Volume                   = {108},

  Abstract                 = {By using high-resolution photoelectron velocity map imaging and a pump-probe ionization scheme we are able to demonstrate that photoelectron angular distributions from ammonia depend sensitively on the neutral rotational level that is ionized, and on the rotational level of the ion that is formed. We use this sensitivity to fully determine the photoionization dynamics giving rise to the observed photoelectron angular distributions and rotational branching ratios. In addition, we observe the dependence of the photoelectron angular distributions on initially prepared alignment, by varying the relative polarizations of pump and probe. This dependence can be used to corroborate the determined photoionization dynamics, and also provides a demonstration that tomographic reconstruction can be used to recreate three-dimensional photoelectron distributions in non-cylindrically symmetric situations. © 2010 Taylor & Francis.},
  Affiliation              = {School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom; Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Author_keywords          = {Intramolecular dynamics; Laser spectroscopy; Orientation and alignment; Photoelectron spectroscopy},
  Document_type            = {Article},
  Doi                      = {10.1080/00268971003639266},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77952927145&partnerID=40&md5=91400872f38cc5dfcd6edc49e8f88479}
}

By using high-resolution photoelectron velocity map imaging and a pump-probe ionization scheme we are able to demonstrate that photoelectron angular distributions from ammonia depend sensitively on the neutral rotational level that is ionized, and on the rotational level of the ion that is formed. We use this sensitivity to fully determine the photoionization dynamics giving rise to the observed photoelectron angular distributions and rotational branching ratios. In addition, we observe the dependence of the photoelectron angular distributions on initially prepared alignment, by varying the relative polarizations of pump and probe. This dependence can be used to corroborate the determined photoionization dynamics, and also provides a demonstration that tomographic reconstruction can be used to recreate three-dimensional photoelectron distributions in non-cylindrically symmetric situations. © 2010 Taylor & Francis.

@Article{Hockett2010a,
  Title                    = {Photoionization dynamics of ammonia (B1E″): Dependence on ionizing photon energy and initial vibrational level},
  Author                   = {Hockett, P.a b , Staniforth, M.a , Reid, K.L.a },
  Journal                  = {Journal of Physical Chemistry A},
  Year                     = {2010},
  Number                   = {42},
  Pages                    = {11330-11336},
  Volume                   = {114},

  Abstract                 = {In this article we present photoelectron spectra and angular distributions in which ion rotational states are resolved. This data enables the comparison of direct and threshold photoionization techniques. We also present angle-resolved photoelectron signals at different total energies, providing a method to scan the structure of the continuum in the near-threshold region. Finally, we have studied the influence of vibrational excitation on the photoionization dynamics. © 2010 American Chemical Society.},
  Affiliation              = {School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom; Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Document_type            = {Article},
  Doi                      = {10.1021/jp104623m},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77958508474&partnerID=40&md5=7a706db748d0f428b96ea557ca4ec1a2}
}

In this article we present photoelectron spectra and angular distributions in which ion rotational states are resolved. This data enables the comparison of direct and threshold photoionization techniques. We also present angle-resolved photoelectron signals at different total energies, providing a method to scan the structure of the continuum in the near-threshold region. Finally, we have studied the influence of vibrational excitation on the photoionization dynamics. © 2010 American Chemical Society.

@Article{Lee2010,
  Title                    = {Comparing phonon dephasing lifetimes in diamond using Transient Coherent Ultrafast Phonon Spectroscopy},
  Author                   = {Lee, K.C.a , Sussman, B.J.a c , Nunn, J.a , Lorenz, V.O.a , Reim, K.a , Jaksch, D.a , Walmsley, I.A.a , Spizzirri, P.b , Prawer, S.b },
  Journal                  = {Diamond and Related Materials},
  Year                     = {2010},
  Number                   = {10},
  Pages                    = {1289-1295},
  Volume                   = {19},

  Abstract                 = {Transient Coherent Ultrafast Phonon Spectroscopy (TCUPS) is utilized to study phonon dephasing lifetimes in various diamond types. Samples of natural, chemical vapour deposited, and high pressure high temperature diamond are compared showing significant differences. Dephasing mechanisms are discussed. © 2010 Elsevier B.V. All rights reserved.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom; Center for Quantum Computer Technology, School of Physics, University of Melbourne, Parkville, VIC 3010, Australia; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada},
  Author_keywords          = {Decoherence; Phonon lifetime; Raman spectroscopy},
  Document_type            = {Article},
  Doi                      = {10.1016/j.diamond.2010.06.002},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77956064176&partnerID=40&md5=c6dc18b1dfbe0564bbca9b2022fc3103}
}

Transient Coherent Ultrafast Phonon Spectroscopy (TCUPS) is utilized to study phonon dephasing lifetimes in various diamond types. Samples of natural, chemical vapour deposited, and high pressure high temperature diamond are compared showing significant differences. Dephasing mechanisms are discussed. © 2010 Elsevier B.V. All rights reserved.

@Conference{Reim2010,
  Title                    = {Applications of Raman scattering in quantum technologies},
  Author                   = {Reim, K.F.a , Bustard, P.a , Lee, K.C.a , Nunn, J.a , Lorenz, V.O.b , Sussman, B.J.c , Langford, N.K.a , Jaksch, D.a , Walmsley, I.A.a },
  Year                     = {2010},
  Pages                    = {37-38},
  Volume                   = {1267},

  Affiliation              = {Department of Physics, University of Oxford, Clarendon Laboratory, Parks Rd., Oxford, OX1 3PU, United Kingdom; Department of Physics, University of Delaware, Newark, DE 19716, United States; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada},
  Document_type            = {Conference Paper},
  Doi                      = {10.1063/1.3482569},
  Journal                  = {AIP Conference Proceedings},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78649936743&partnerID=40&md5=199fda10b1d029be2e42afbf5bf7ef3f}
}

@Article{Reim2010a,
  Title                    = {Towards high-speed optical quantum memories},
  Author                   = {Reim, K.F.a , Nunn, J.a , Lorenz, V.O.a b , Sussman, B.J.a c , Lee, K.C.a , Langford, N.K.a , Jaksch, D.a , Walmsley, I.A.a },
  Journal                  = {Nature Photonics},
  Year                     = {2010},
  Number                   = {4},
  Pages                    = {218-221},
  Volume                   = {4},

  Abstract                 = {Quantum memories, capable of controllably storing and releasing a photon, are a crucial component for quantum computers1 and quantum communications2. To date, quantum memories3-6 have operated with bandwidths that limit data rates to megahertz. Here we report the coherent storage and retrieval of sub-nanosecond low-intensity light pulses with spectral bandwidths exceeding 1GHz in caesium vapour. The novel memory interaction takes place through a far off-resonant two-photon transition in which the memory bandwidth is dynamically generated by a strong control field7,8. This should allow data rates more than 100 times greater than those of existing quantum memories. The memory works with a total efficiency of 15%, and its coherence is demonstrated through direct interference of the stored and retrieved pulses. Coherence times in hot atomic vapours are on the order of microseconds, the expected storage time limit for this memory. © 2010 Macmillan Publishers Limited. All rights reserved.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom; Department of Physics, University of Delaware, Newark, DE 19716, United States; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada},
  Document_type            = {Article},
  Doi                      = {10.1038/nphoton.2010.30},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77950498106&partnerID=40&md5=505bbd356f7cb2160daebfd006d725dd}
}

Quantum memories, capable of controllably storing and releasing a photon, are a crucial component for quantum computers1 and quantum communications2. To date, quantum memories3-6 have operated with bandwidths that limit data rates to megahertz. Here we report the coherent storage and retrieval of sub-nanosecond low-intensity light pulses with spectral bandwidths exceeding 1GHz in caesium vapour. The novel memory interaction takes place through a far off-resonant two-photon transition in which the memory bandwidth is dynamically generated by a strong control field7,8. This should allow data rates more than 100 times greater than those of existing quantum memories. The memory works with a total efficiency of 15%, and its coherence is demonstrated through direct interference of the stored and retrieved pulses. Coherence times in hot atomic vapours are on the order of microseconds, the expected storage time limit for this memory. © 2010 Macmillan Publishers Limited. All rights reserved.

@Conference{Reim2010b,
  Title                    = {Coherent optical memory with GHz bandwidth},
  Author                   = {Reim, K.F.a , Nunn, J.a , Lorenz, V.O.b , Sussman, B.J.a c , Lee, K.C.a , Langford, N.K.a , Jaksch, D.a , Walmsley, I.A.a },
  Year                     = {2010},

  Abstract                 = {We demonstrate the coherent storage and retrieval of sub-nanosecond low-intensity light pulses with spectral bandwidths exceeding 1 GHz in cesium vapor, using the novel, far offresonant two-photon Raman memory protocol. © 2010 Optical Society of America.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom; Department of Physics, University of Delaware, Newark, DE 19716, United States; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {5501221},
  Document_type            = {Conference Paper},
  Journal                  = {Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference: 2010 Laser Science to Photonic Applications, CLEO/QELS 2010},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77957574214&partnerID=40&md5=3e29e46b5df1ec4f674e0006129fb177}
}

We demonstrate the coherent storage and retrieval of sub-nanosecond low-intensity light pulses with spectral bandwidths exceeding 1 GHz in cesium vapor, using the novel, far offresonant two-photon Raman memory protocol. © 2010 Optical Society of America.

@Article{Weeraman2010,
  Title                    = {Vibrational sum frequency generation spectroscopy using inverted visible pulses},
  Author                   = {Weeraman, C., Mitchell, S.A., Lausten, R., Johnston, L.J., Stolow, A.},
  Journal                  = {Optics Express},
  Year                     = {2010},
  Number                   = {11},
  Pages                    = {11483-11494},
  Volume                   = {18},

  Abstract                 = {We present a broadband vibrational sum frequency generation (BB-VSFG) scheme using a novel ps visible pulse shape. We generate the fs IR pulse via standard procedures and simultaneously generate an 'inverted' time-asymmetric narrowband ps visible pulse via second harmonic generation in the pump depletion regime using a very long nonlinear crystal which has high group velocity mismatch (LiNbO3). The 'inverted' ps pulse shape minimally samples the instantaneous nonresonant response but maximally samples the resonant response, maintaining high spectral resolution. We experimentally demonstrate this scheme, presenting SFG spectra of canonical organic monolayer systems in the C-H stretch region (2800-3000 cm-1). © 2010 OSA.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Document_type            = {Article},
  Doi                      = {10.1364/OE.18.011483},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77952793730&partnerID=40&md5=57996fe7147cc0178d6db55371c5ec19}
}

We present a broadband vibrational sum frequency generation (BB-VSFG) scheme using a novel ps visible pulse shape. We generate the fs IR pulse via standard procedures and simultaneously generate an 'inverted' time-asymmetric narrowband ps visible pulse via second harmonic generation in the pump depletion regime using a very long nonlinear crystal which has high group velocity mismatch (LiNbO3). The 'inverted' ps pulse shape minimally samples the instantaneous nonresonant response but maximally samples the resonant response, maintaining high spectral resolution. We experimentally demonstrate this scheme, presenting SFG spectra of canonical organic monolayer systems in the C-H stretch region (2800-3000 cm-1). © 2010 OSA.

@Article{Hockett2009,
  Title                    = {Rotationally resolved photoelectron angular distributions from a nonlinear polyatomic molecule},
  Author                   = {Hockett, P.a , Staniforth, M.a , Reid, K.L.a , Townsend, D.b },
  Journal                  = {Physical Review Letters},
  Year                     = {2009},
  Number                   = {25},
  Volume                   = {102},

  Abstract                 = {We present, for the first time, rotationally resolved photoelectron images resulting from the ionization of a polyatomic molecule. Photoelectron angular distributions pertaining to the formation of individual rotational levels of NH3+ have been extracted from the images and analyzed to enable a complete determination of the radial dipole matrix elements and relative phases that describe the ionization dynamics. This determination leads to the deduction of significantly different dynamics from those extracted in previous studies which lacked either angular information or rotational resolution. © 2009 The American Physical Society.},
  Affiliation              = {School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom; School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom},
  Art_number               = {253002},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.102.253002},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-67649304902&partnerID=40&md5=80704cee0c2bce1d38f6ba99ead600a1}
}

We present, for the first time, rotationally resolved photoelectron images resulting from the ionization of a polyatomic molecule. Photoelectron angular distributions pertaining to the formation of individual rotational levels of NH3+ have been extracted from the images and analyzed to enable a complete determination of the radial dipole matrix elements and relative phases that describe the ionization dynamics. This determination leads to the deduction of significantly different dynamics from those extracted in previous studies which lacked either angular information or rotational resolution. © 2009 The American Physical Society.

@Article{Martay2009a,
  Title                    = {Demonstrating coherent control in R 85 b2 using ultrafast laser pulses: A theoretical outline of two experiments},
  Author                   = {Martay, H.E.L., McCabe, D.J., England, D.G., Friedman, M.E., Petrovic, J., Walmsley, I.A.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2009},
  Number                   = {3},
  Volume                   = {80},

  Abstract                 = {Calculations relating to two experiments that demonstrate coherent control of preformed rubidium-85 molecules in a magneto-optical trap using ultrafast laser pulses are presented. The two experiments are a step toward the stabilization of ultracold rubidium dimers using ultrafast lasers. In the first experiment, it is shown that preassociated molecules in an incoherent mixture of states can be made to oscillate coherently using a single ultrafast pulse. A mechanism that can transfer molecular population to more deeply bound vibrational levels is used in the second. Optimal parameters of the control pulse are presented for the application of the mechanism to molecules in a magneto-optical trap. The calculations make use of an experimental determination of the initial state of molecules photoassociated by the trapping lasers in the magneto-optical trap and use shaped pulses consistent with a standard ultrafast laser system. The experiment's purpose is to demonstrate and evaluate the use of ultrafast shaped pulses to manipulate ultracold rubidium dimers with a view to the eventual stabilization of the molecules. © 2009 The American Physical Society.},
  Affiliation              = {Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom},
  Art_number               = {033403},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.80.033403},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-69849095792&partnerID=40&md5=135c1354bca9c5128757ab5a8feb48b7}
}

Calculations relating to two experiments that demonstrate coherent control of preformed rubidium-85 molecules in a magneto-optical trap using ultrafast laser pulses are presented. The two experiments are a step toward the stabilization of ultracold rubidium dimers using ultrafast lasers. In the first experiment, it is shown that preassociated molecules in an incoherent mixture of states can be made to oscillate coherently using a single ultrafast pulse. A mechanism that can transfer molecular population to more deeply bound vibrational levels is used in the second. Optimal parameters of the control pulse are presented for the application of the mechanism to molecules in a magneto-optical trap. The calculations make use of an experimental determination of the initial state of molecules photoassociated by the trapping lasers in the magneto-optical trap and use shaped pulses consistent with a standard ultrafast laser system. The experiment's purpose is to demonstrate and evaluate the use of ultrafast shaped pulses to manipulate ultracold rubidium dimers with a view to the eventual stabilization of the molecules. © 2009 The American Physical Society.

@Article{Martay2009b,
  Title                    = {Erratum: Demonstrating coherent control in R 85 b2 using ultrafast laser pulses: A theoretical outline of two experiments (Physical Review A - Atomic, Molecular, and Optical Physics (2009) 80 (033403))},
  Author                   = {Martay, H.E.L., McCabe, D.J., England, D.G., Friedman, M.E., Petrovic, J., Walmsley, I.A.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2009},
  Number                   = {3},
  Volume                   = {80},

  Art_number               = {039901},
  Document_type            = {Erratum},
  Doi                      = {10.1103/PhysRevA.80.039901},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70349096700&partnerID=40&md5=15b3d2db2ee45b37bbffe6b17730ad23}
}

@Conference{Martay2009,
  Title                    = {Dynamic wavepackets in coherently controlled rubidium dimers},
  Author                   = {Martay, H.E.L., McCabe, D.J., England, D.G., Friedman-Yalonetzky, M.E., Petrovic, J., Walmsley, I.A.},
  Year                     = {2009},

  Affiliation              = {Oxford University, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom},
  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84898035409&partnerID=40&md5=bf0c5b87152d740ef0962bbd3b730597}
}

@Conference{McCabe2009,
  Title                    = {A pump-probe study of the photoassociation of cold rubidium molecules},
  Author                   = {McCabe, D.J., England, D.G., Martay, H.E.L., Friedman-Yalonetzky, M.E., Dimova, E., Petrovic, J., Walmsley, I.A.},
  Year                     = {2009},

  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU, United Kingdom},
  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84898027736&partnerID=40&md5=376361e54878c51229a29062fdcdb53c}
}

@Article{McCabe2009a,
  Title                    = {Pump-probe study of the formation of rubidium molecules by ultrafast photoassociation of ultracold atoms},
  Author                   = {McCabe, D.J.a , England, D.G.a , Martay, H.E.L.a , Friedman, M.E.a , Petrovic, J.a , Dimova, E.b , Chatel, B.c , Walmsley, I.A.a },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2009},
  Number                   = {3},
  Volume                   = {80},

  Abstract                 = {An experimental pump-probe study of the photoassociative creation of translationally ultracold rubidium molecules is presented together with numerical simulations of the process. The formation of loosely bound excited-state dimers is observed as a first step toward a fully coherent pump-dump approach to the stabilization of Rb2 into its lowest ground vibrational states. The population that contributes to the pump-probe process is characterized and found to be distinct from a background population of preassociated molecules. © 2009 The American Physical Society.},
  Affiliation              = {Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom; Institute of Solid State Physics, 72 Tzarigradsko Chaussee, 1784 Sofia, Bulgaria; UPS, Laboratoire Collisions, CNRS-Université de Toulouse, F-31062 Toulouse, France},
  Art_number               = {033404},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.80.033404},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-69849100854&partnerID=40&md5=72e7fa7a1002599a8af79ec47d1e6dc6}
}

An experimental pump-probe study of the photoassociative creation of translationally ultracold rubidium molecules is presented together with numerical simulations of the process. The formation of loosely bound excited-state dimers is observed as a first step toward a fully coherent pump-dump approach to the stabilization of Rb2 into its lowest ground vibrational states. The population that contributes to the pump-probe process is characterized and found to be distinct from a background population of preassociated molecules. © 2009 The American Physical Society.

@Conference{Pegoraro2009,
  Title                    = {All-Fiber multimodal CARS microscopy of live cells},
  Author                   = {Pegoraro, A.F.a b , Ridsdale, A.a , Lausten, R.a b , Moffatt, D.J.a , Stolow, A.a b , Thomas, B.K.c , Fu, L.c , Dong, L.c , Fermann, M.E.c },
  Year                     = {2009},

  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council Canada, 100 Sussex Dr., Ottawa, ON, K1A 0R6, Canada; Department of Physics, Queen's University, 99 University Avenue, Kingston, Ontario, K7L 3N6, Canada; IMRA America Inc., 1044 Woodridge Ave., Ann Arbor, MI, 48105, United States},
  Document_type            = {Conference Paper},
  Journal                  = {Optics InfoBase Conference Papers},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84897959930&partnerID=40&md5=4ad9ba751a9dba1bcdc4cb1ebe7a57aa}
}

@Article{Petrovic2009,
  Title                    = {A pump-probe study of the photoassociation of cold rubidium molecules},
  Author                   = {Petrovic, J.a , McCabe, D.a , England, D.a , Martay, H.a , Friedman, M.a , Dicks, A.a , Dimova, E.b , Walmsley, I.a },
  Journal                  = {Faraday Discussions},
  Year                     = {2009},
  Pages                    = {403-413},
  Volume                   = {142},

  Abstract                 = {The dynamics of the excited state during the photoassociation of cold molecules from cold rubidium atoms is studied in a series of pump-probe experiments. Dipole transitions similar to those of the atoms are observed in the molecular signal. While such behaviour is characteristic of the long-range molecules, the photoassociation of bound molecules is confirmed in additional experiments. The pump-probe signal observed on a 250 ps time scale did not, however, reveal wavepacket oscillations predicted by theory. This result is discussed using numerical simulations of photoassociation and a modification to the current experiments that could lead to the detection of wavepacket dynamics is suggested. © 2009 The Royal Society of Chemistry.},
  Affiliation              = {Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom; Institute of Solid State Physics Acad. G. Nadjakov, Bulgarian Academy of Science, 72 Tzarigradsko Shoussee, 1784 Sofia, Bulgaria},
  Document_type            = {Article},
  Doi                      = {10.1039/b818494a},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70349280074&partnerID=40&md5=94ef833a78b0102fe35664859e4c388d}
}

The dynamics of the excited state during the photoassociation of cold molecules from cold rubidium atoms is studied in a series of pump-probe experiments. Dipole transitions similar to those of the atoms are observed in the molecular signal. While such behaviour is characteristic of the long-range molecules, the photoassociation of bound molecules is confirmed in additional experiments. The pump-probe signal observed on a 250 ps time scale did not, however, reveal wavepacket oscillations predicted by theory. This result is discussed using numerical simulations of photoassociation and a modification to the current experiments that could lead to the detection of wavepacket dynamics is suggested. © 2009 The Royal Society of Chemistry.

@Article{Lausten2008,
  Title                    = {Time- and frequency-resolved coherent anti-Stokes Raman scattering spectroscopy with sub- 25 fs laser pulses},
  Author                   = {Lausten, R.a b , Smirnova, O.b , Sussman, B.J.a , Gräfe, S.b , Mouritzen, A.S.c , Stolow, A.a b },
  Journal                  = {Journal of Chemical Physics},
  Year                     = {2008},
  Number                   = {24},
  Volume                   = {128},

  Abstract                 = {In general, many different diagrams can contribute to the signal measured in broadband four-wave mixing experiments. Care must therefore be taken when designing an experiment to be sensitive to only the desired diagram by taking advantage of phase matching, pulse timing, sequence, and the wavelengths employed. We use sub- 25 fs pulses to create and monitor vibrational wavepackets in gaseous iodine, bromine, and iodine bromide through time- and frequency-resolved femtosecond coherent anti-Stokes Raman scattering (CARS) spectroscopy. We experimentally illustrate this using iodine, where the broad bandwidths of our pulses, and Boltzmann population in the lower three vibrational levels conspire to make a single diagram dominant in one spectral region of the signal spectrum. In another spectral region, however, the signal is the sum of two almost equally contributing diagrams, making it difficult to directly extract information about the molecular dynamics. We derive simple analytical expressions for the time- and frequency-resolved CARS signal to study the interplay of different diagrams. Expressions are given for all five diagrams which can contribute to the CARS signal in our case. © 2008 American Institute of Physics.},
  Affiliation              = {Department of Physics, Queen's University, Kingston, ON K7L 3N6, Canada; Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada; Department of Physics and Astronomy, University of Aarhus, DK-8000 Århus C, Denmark},
  Art_number               = {244310},
  Document_type            = {Article},
  Doi                      = {10.1063/1.2932101},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-46149110109&partnerID=40&md5=7a7ef88bf3f6b5355b09ef3839f50e3b}
}

In general, many different diagrams can contribute to the signal measured in broadband four-wave mixing experiments. Care must therefore be taken when designing an experiment to be sensitive to only the desired diagram by taking advantage of phase matching, pulse timing, sequence, and the wavelengths employed. We use sub- 25 fs pulses to create and monitor vibrational wavepackets in gaseous iodine, bromine, and iodine bromide through time- and frequency-resolved femtosecond coherent anti-Stokes Raman scattering (CARS) spectroscopy. We experimentally illustrate this using iodine, where the broad bandwidths of our pulses, and Boltzmann population in the lower three vibrational levels conspire to make a single diagram dominant in one spectral region of the signal spectrum. In another spectral region, however, the signal is the sum of two almost equally contributing diagrams, making it difficult to directly extract information about the molecular dynamics. We derive simple analytical expressions for the time- and frequency-resolved CARS signal to study the interplay of different diagrams. Expressions are given for all five diagrams which can contribute to the CARS signal in our case. © 2008 American Institute of Physics.

@Article{Nunn2008,
  Title                    = {Multimode memories in atomic ensembles},
  Author                   = {Nunn, J.a , Reim, K.a , Lee, K.C.a , Lorenz, V.O.a , Sussman, B.J.a b , Walmsley, I.A.a , Jaksch, D.a },
  Journal                  = {Physical Review Letters},
  Year                     = {2008},
  Number                   = {26},
  Volume                   = {101},

  Abstract                 = {The ability to store multiple optical modes in a quantum memory allows for increased efficiency of quantum communication and computation. Here we compute the multimode capacity of a variety of quantum memory protocols based on light storage in ensembles of atoms. We find that adding a controlled inhomogeneous broadening improves this capacity significantly. © 2008 The American Physical Society.},
  Affiliation              = {Clarendon Laboratory, Oxford University, Parks Road, Oxford OX1 3PU, United Kingdom; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {260502},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.101.260502},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-58149236717&partnerID=40&md5=76272e2446189eaaddd551678a3b18d8}
}

The ability to store multiple optical modes in a quantum memory allows for increased efficiency of quantum communication and computation. Here we compute the multimode capacity of a variety of quantum memory protocols based on light storage in ensembles of atoms. We find that adding a controlled inhomogeneous broadening improves this capacity significantly. © 2008 The American Physical Society.

@Article{Surmacz2008,
  Title                    = {Efficient spatially resolved multimode quantum memory},
  Author                   = {Surmacz, K., Nunn, J., Reim, K., Lee, K.C., Lorenz, V.O., Sussman, B., Walmsley, I.A., Jaksch, D.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2008},
  Number                   = {3},
  Volume                   = {78},

  Abstract                 = {Light storage in atomic ensembles has been implemented successfully, but the retrieval efficiency can be low. We propose to improve this efficiency with appropriately phase-matched backward propagating retrieval. This method allows for easy spatial filtering of the retrieved light; in addition, multiple optical modes can be stored in the transverse momentum of the ensemble. We model walk-off effects with a full numerical simulation, and confirm the applicability of the scheme. © 2008 The American Physical Society.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom},
  Art_number               = {033806},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.78.033806},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-51649114295&partnerID=40&md5=452158b9cf73f1a0615a0be5063cbffe}
}

Light storage in atomic ensembles has been implemented successfully, but the retrieval efficiency can be low. We propose to improve this efficiency with appropriately phase-matched backward propagating retrieval. This method allows for easy spatial filtering of the retrieved light; in addition, multiple optical modes can be stored in the transverse momentum of the ensemble. We model walk-off effects with a full numerical simulation, and confirm the applicability of the scheme. © 2008 The American Physical Society.

@Article{Sussman2008,
  Title                    = {Focusing of light following a 4- f pulse shaper: Considerations for quantum control},
  Author                   = {Sussman, B.J., Lausten, R., Stolow, A.},
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2008},
  Number                   = {4},
  Volume                   = {77},

  Abstract                 = {The focusing of coherent light, modified by a spatial light modulator (SLM) based 4- f pulse shaper, is discussed in the context of scalar diffraction theory. Diffractive effects (including space-time coupling) in SLMs may alter the size and shape of a subsequent laser focus. A numerical approach is used to investigate the effects of some common phase masks on the properties of the laser focus. The extreme case of an alternating phase mask is considered in some detail, as it clearly illustrates the effects of space-time coupling. The results are compared to a simple analytic model. The potential influence of SLM diffractive effects on multiphoton quantum control studies is discussed and some approaches to minimizing undesirable diffractive effects are suggested. © 2008 The American Physical Society.},
  Affiliation              = {Molecular Photonics, Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {043416},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.77.043416},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-42549150965&partnerID=40&md5=63acf0381f960fbcd01d4466b6442a9b}
}

The focusing of coherent light, modified by a spatial light modulator (SLM) based 4- f pulse shaper, is discussed in the context of scalar diffraction theory. Diffractive effects (including space-time coupling) in SLMs may alter the size and shape of a subsequent laser focus. A numerical approach is used to investigate the effects of some common phase masks on the properties of the laser focus. The extreme case of an alternating phase mask is considered in some detail, as it clearly illustrates the effects of space-time coupling. The results are compared to a simple analytic model. The potential influence of SLM diffractive effects on multiphoton quantum control studies is discussed and some approaches to minimizing undesirable diffractive effects are suggested. © 2008 The American Physical Society.

@Article{Waldermann2008,
  Title                    = {Measuring phonon dephasing with ultrafast pulses using Raman spectral interference},
  Author                   = {Waldermann, F.C.a , Sussman, B.J.a c , Nunn, J.a , Lorenz, V.O.a , Lee, K.C.a , Surmacz, K.a , Lee, K.H.a , Jaksch, D.a , Walmsley, I.A.a , Spizziri, P.b , Olivero, P.b , Prawer, S.b },
  Journal                  = {Physical Review B - Condensed Matter and Materials Physics},
  Year                     = {2008},
  Number                   = {15},
  Volume                   = {78},

  Abstract                 = {A technique to measure the decoherence time of optical phonons in a solid is presented. Phonons are excited with a pair of time-delayed 80 fs near infrared pulses via spontaneous transient Raman scattering. The spectral fringe visibility of the resulting Raman pulse pair, as a function of time delay, is used to measure the phonon dephasing time. The method avoids the need to use either narrow band or few femtosecond pulses and is useful for low phonon excitations. The dephasing time of phonons created in bulk diamond is measured to be τ=6.8 ps (Δν=1.56 cm-1). ©2008 The American Physical Society.},
  Affiliation              = {Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom; Center for Quantum Computer Technology, School of Physics, University of Melbourne, Parkville, VIC 3010, Australia; National Research Council of Canada, Ottawa, ON K1A 0R6, Canada},
  Art_number               = {155201},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevB.78.155201},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-54449091796&partnerID=40&md5=27af96f6e1ec8d3f9cb2d89b562344b2}
}

A technique to measure the decoherence time of optical phonons in a solid is presented. Phonons are excited with a pair of time-delayed 80 fs near infrared pulses via spontaneous transient Raman scattering. The spectral fringe visibility of the resulting Raman pulse pair, as a function of time delay, is used to measure the phonon dephasing time. The method avoids the need to use either narrow band or few femtosecond pulses and is useful for low phonon excitations. The dephasing time of phonons created in bulk diamond is measured to be τ=6.8 ps (Δν=1.56 cm-1). ©2008 The American Physical Society.

@Article{Hockett2007,
  Title                    = {Complete determination of the photoionization dynamics of a polyatomic molecule. I. Experimental photoelectron angular distributions from à Au1 acetylene},
  Author                   = {Hockett, P., King, A.K., Powis, I., Reid, K.L.},
  Journal                  = {Journal of Chemical Physics},
  Year                     = {2007},
  Number                   = {15},
  Volume                   = {127},

  Abstract                 = {Angle-resolved photoelectron spectra from rotationally selected à Au1 state acetylene have been recorded using velocity-map imaging. Several Renner-Teller split vibrational bands have been observed and assigned, showing good agreement with previous zero kinetic energy photoelectron (ZEKE) work [S. T. Pratt, P. M. Dehmer, and J. L. Dehmer, J. Chem. Phys. 99, 6233 (1993); S.-J. Tang, Y.-C. Chou, J. J.-M. Lin, and Y.-C. Hsu, ibid. 125, 133201 (2006).] The extracted photoelectron angular distributions (PADs) corresponding to these bands show a strong dependence on the vibronic angular momentum projection quantum number K+. Subbands with odd K+ show PADs with maximum intensity along the polarization vector of the ionizing laser beam, while those with even K+ show PADs with maximum intensity perpendicular to this direction. Velocity-map images recorded at low photoelectron energies approach rotational resolution of the ion, and the evolution of the PADs with increasing rotational level prepared in the à Au1 state indicates the potential of a "complete" determination of the photoionization dynamics of the à Au1 state. This is further investigated in the following paper. © 2007 American Institute of Physics.},
  Affiliation              = {School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom},
  Art_number               = {154307},
  Document_type            = {Article},
  Doi                      = {10.1063/1.2790442},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-39349090837&partnerID=40&md5=2c5ab209e45a44d6714b3f55db7a4fdb}
}

Angle-resolved photoelectron spectra from rotationally selected à Au1 state acetylene have been recorded using velocity-map imaging. Several Renner-Teller split vibrational bands have been observed and assigned, showing good agreement with previous zero kinetic energy photoelectron (ZEKE) work [S. T. Pratt, P. M. Dehmer, and J. L. Dehmer, J. Chem. Phys. 99, 6233 (1993); S.-J. Tang, Y.-C. Chou, J. J.-M. Lin, and Y.-C. Hsu, ibid. 125, 133201 (2006).] The extracted photoelectron angular distributions (PADs) corresponding to these bands show a strong dependence on the vibronic angular momentum projection quantum number K+. Subbands with odd K+ show PADs with maximum intensity along the polarization vector of the ionizing laser beam, while those with even K+ show PADs with maximum intensity perpendicular to this direction. Velocity-map images recorded at low photoelectron energies approach rotational resolution of the ion, and the evolution of the PADs with increasing rotational level prepared in the à Au1 state indicates the potential of a "complete" determination of the photoionization dynamics of the à Au1 state. This is further investigated in the following paper. © 2007 American Institute of Physics.

@Article{Hockett2007a,
  Title                    = {Complete determination of the photoionization dynamics of a polyatomic molecule. II. Determination of radial dipole matrix elements and phases from experimental photoelectron angular distributions from à Au1 acetylene},
  Author                   = {Hockett, P., Reid, K.L.},
  Journal                  = {Journal of Chemical Physics},
  Year                     = {2007},
  Number                   = {15},
  Volume                   = {127},

  Abstract                 = {We present a fit to photoelectron angular distributions (PADs) measured following the photoionization of rotationally selected à Au1 state acetylene. In the case of the 41 u-2 vibronic state of the ion, we are able to use this fit to make a complete determination of the radial dipole matrix elements and phases connecting the prepared level to each photoelectron partial wave. We have also investigated other Renner-Teller subbands with a view to disentangling geometrical and dynamical contributions to the resulting PADs. © 2007 American Institute of Physics.},
  Affiliation              = {School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom},
  Art_number               = {154308},
  Document_type            = {Article},
  Doi                      = {10.1063/1.2790443},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-39349087960&partnerID=40&md5=05d943fab2249bf0c582723467b1d8dd}
}

We present a fit to photoelectron angular distributions (PADs) measured following the photoionization of rotationally selected à Au1 state acetylene. In the case of the 41 u-2 vibronic state of the ion, we are able to use this fit to make a complete determination of the radial dipole matrix elements and phases connecting the prepared level to each photoelectron partial wave. We have also investigated other Renner-Teller subbands with a view to disentangling geometrical and dynamical contributions to the resulting PADs. © 2007 American Institute of Physics.

@Article{Sussman2006b,
  Title                    = {Dynamic stark control of photochemical processes},
  Author                   = {Sussman, B.J.a b , Townsend, D.a , Ivanov, M.Yu.a , Stolow, A.a b },
  Journal                  = {Science},
  Year                     = {2006},
  Number                   = {5797},
  Pages                    = {278-281},
  Volume                   = {314},

  Abstract                 = {A method is presented for controlling the outcome of photochemical reactions by using the dynamic Stark effect due to a strong, nonresonant infrared field. The application of a precisely timed infrared laser pulse reversibly modifies potential energy barriers during a chemical reaction without inducing any real electronic transitions. Dynamic Stark control (DSC) is experimentally demonstrated for a nonadiabatic photochemical reaction, showing substantial modification of reaction channel probabilities in the dissociation of IBr. The DSC process is nonperturbative and insensitive to laser frequency and affects all polarizable molecules, suggesting broad applicability.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ont. K1A 0R6, Canada; Department of Physics, Queen's University, Kingston, Ont. K7L 3N6, Canada},
  Document_type            = {Article},
  Doi                      = {10.1126/science.1132289},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33750007803&partnerID=40&md5=04996fa3e437b0795b4a8f814b56afc4}
}

A method is presented for controlling the outcome of photochemical reactions by using the dynamic Stark effect due to a strong, nonresonant infrared field. The application of a precisely timed infrared laser pulse reversibly modifies potential energy barriers during a chemical reaction without inducing any real electronic transitions. Dynamic Stark control (DSC) is experimentally demonstrated for a nonadiabatic photochemical reaction, showing substantial modification of reaction channel probabilities in the dissociation of IBr. The DSC process is nonperturbative and insensitive to laser frequency and affects all polarizable molecules, suggesting broad applicability.

@Article{Sussman2006,
  Title                    = {Quantum control via the dynamic Stark effect: Application to switched rotational wave packets and molecular axis alignment},
  Author                   = {Sussman, B.J.a b , Underwood, J.G.c , Lausten, R.a b , Ivanov, M.Y.a , Stolow, A.a b },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2006},
  Number                   = {5},
  Volume                   = {73},

  Abstract                 = {Nonperturbative quantum control schemes in the intermediate field strength (nonionizing) regime are investigated. We restrict the matter-field interaction to the nonresonant dynamic Stark effect (NRDSE) as induced by infrared laser fields, which we argue is a new and general tool for quantum control of atomic and molecular dynamics. For the case of Raman coupled matter states, an effective Hamiltionian may be constructed, and quantum control via NRDSE may be thought of as reversibly modifying the effective Hamiltonian during system propagation, thus leading to control over dynamic processes. As an illustration, the creation of field-free "switched" wave packets through the adiabatic turn on and sudden turn off of the NRDSE is considered and experimentally demonstrated. Wave packets generated through the switched NRDSE interaction may be very different in form and content than wave packets generated via resonant transitions with Gaussian optical pulses. In order to provide an example, we discuss the specific case of rotational wave packet dynamics where the NRDSE manifests itself as molecular axis alignment. This technique is applied to the creation of field-free molecular axis alignment using an intense switched 1.064 μm laser pulse. This switched laser pulse was generated via a plasma shuttering technique, giving a pulse with a rise time of 150 ps and a fall time of 170 fs. The temporal evolution of the molecular axis alignment is probed via the optical Kerr effect. Field-free alignment via the switched NRDSE is demonstrated for both linear (CO2, C S2) and symmetric top (1,2-propadiene) polyatomic molecules. © 2006 The American Physical Society.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ont. K1A 0R6, Canada; Department of Physics, Queen's University, Kingston, Ont. K7L 3N6, Canada; Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom},
  Art_number               = {053403},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.73.053403},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33646417943&partnerID=40&md5=48f516d2f583f2adc49329f8b26ffbf1}
}

Nonperturbative quantum control schemes in the intermediate field strength (nonionizing) regime are investigated. We restrict the matter-field interaction to the nonresonant dynamic Stark effect (NRDSE) as induced by infrared laser fields, which we argue is a new and general tool for quantum control of atomic and molecular dynamics. For the case of Raman coupled matter states, an effective Hamiltionian may be constructed, and quantum control via NRDSE may be thought of as reversibly modifying the effective Hamiltonian during system propagation, thus leading to control over dynamic processes. As an illustration, the creation of field-free "switched" wave packets through the adiabatic turn on and sudden turn off of the NRDSE is considered and experimentally demonstrated. Wave packets generated through the switched NRDSE interaction may be very different in form and content than wave packets generated via resonant transitions with Gaussian optical pulses. In order to provide an example, we discuss the specific case of rotational wave packet dynamics where the NRDSE manifests itself as molecular axis alignment. This technique is applied to the creation of field-free molecular axis alignment using an intense switched 1.064 μm laser pulse. This switched laser pulse was generated via a plasma shuttering technique, giving a pulse with a rise time of 150 ps and a fall time of 170 fs. The temporal evolution of the molecular axis alignment is probed via the optical Kerr effect. Field-free alignment via the switched NRDSE is demonstrated for both linear (CO2, C S2) and symmetric top (1,2-propadiene) polyatomic molecules. © 2006 The American Physical Society.

@Article{Lausten2005,
  Title                    = {Optically reconfigurable azobenzene polymer-based fiber Bragg filter},
  Author                   = {Lausten, R.a , Rochon, P.b , Ivanov, M.b , Cheben, P.c , Janz, S.c , Desjardins, P.d , Ripmeester, J.d , Siebert, T.d , Stolow, A.d },
  Journal                  = {Applied Optics},
  Year                     = {2005},
  Number                   = {33},
  Pages                    = {7039-7042},
  Volume                   = {44},

  Abstract                 = {Optically writable, thermally erasable surface relief gratings in thin Disperse Red 1 polymethyl methacrylate azopolymer films were used to demonstrate an arbitrarily reconfigurable fiber Bragg filter. Gratings were optically written on azopolymer-coated side-polished fiber blocks, and a write-erase-write cycle was demonstrated. Finite difference time domain simulations reveal that this optically reconfigurable device concept can be optimized hi a silicon-on-insulator waveguide platform. © 2005 Optical Society of America.},
  Affiliation              = {Department of Physics, Queen's University, Kingston, Ont. K7L 3N6, Canada; Department of Physics, Royal Military College, Kingston, Ont. K7K 7B4, Canada; Institute for Microstructural Sciences, National Research Council of Canada, Ottawa, Ont. K1A 0R6, Canada; Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ont. K1A 0R6, Canada},
  Document_type            = {Article},
  Doi                      = {10.1364/AO.44.007039},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-29144443455&partnerID=40&md5=ad8f2431cfe29b3906b27e86bf8d087c}
}

Optically writable, thermally erasable surface relief gratings in thin Disperse Red 1 polymethyl methacrylate azopolymer films were used to demonstrate an arbitrarily reconfigurable fiber Bragg filter. Gratings were optically written on azopolymer-coated side-polished fiber blocks, and a write-erase-write cycle was demonstrated. Finite difference time domain simulations reveal that this optically reconfigurable device concept can be optimized hi a silicon-on-insulator waveguide platform. © 2005 Optical Society of America.

@Article{Sussman2005,
  Title                    = {Nonperturbative quantum control via the nonresonant dynamic Stark effect},
  Author                   = {Sussman, B.J.a b , Ivanov, M.Yu.a , Stolow, A.a b },
  Journal                  = {Physical Review A - Atomic, Molecular, and Optical Physics},
  Year                     = {2005},
  Number                   = {5},
  Volume                   = {71},

  Abstract                 = {The nonresonant dynamic Stark effect (NRDSE) is investigated as a general tool for quantum control in the intermediate field strength regime (nonperturbative but nonionizing). We illustrate this scheme for the case of nonadiabatic molecular photodissociation at an avoided crossing. Using the NRDSE exclusively, both the electronic branching ratio and predissociation lifetime may be controlled. Infrared control pulses are used to modify the field-free dynamical evolution during traversal of the avoided crossing, thus controlling the nonadiabatic branching ratio. Predissociation lifetimes may be either increased or decreased using properly timed short infrared pulses to modify phase differences between the diabatic wave packets. In contrast with the limiting cases of perturbative control (interference between transitions) and strong field control with ionizing laser fields, control via the NRDSE may be thought of as reversibly modifying the effective Hamiltonian during system propagation. © 2005 The American Physical Society.},
  Affiliation              = {Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ont. K1A 0R6, Canada; Department of Physics, Queen's University, Kingston, Ont. K7L 3N6, Canada},
  Art_number               = {051401},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevA.71.051401},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-26944456640&partnerID=40&md5=772f02aae1c879af2cd2720f77fdc864}
}

The nonresonant dynamic Stark effect (NRDSE) is investigated as a general tool for quantum control in the intermediate field strength regime (nonperturbative but nonionizing). We illustrate this scheme for the case of nonadiabatic molecular photodissociation at an avoided crossing. Using the NRDSE exclusively, both the electronic branching ratio and predissociation lifetime may be controlled. Infrared control pulses are used to modify the field-free dynamical evolution during traversal of the avoided crossing, thus controlling the nonadiabatic branching ratio. Predissociation lifetimes may be either increased or decreased using properly timed short infrared pulses to modify phase differences between the diabatic wave packets. In contrast with the limiting cases of perturbative control (interference between transitions) and strong field control with ionizing laser fields, control via the NRDSE may be thought of as reversibly modifying the effective Hamiltonian during system propagation. © 2005 The American Physical Society.

@Article{Underwood2005,
  Title                    = {Field-free three dimensional molecular axis alignment},
  Author                   = {Underwood, J.G.a , Sussman, B.J.b c , Stolow, A.b c },
  Journal                  = {Physical Review Letters},
  Year                     = {2005},
  Number                   = {14},
  Volume                   = {94},

  Abstract                 = {We investigate strategies for field-free three dimensional molecular axis alignment using strong nonresonant laser fields under experimentally realistic conditions. Using the polarizabilites and rotational constants of an asymmetric top rotor molecule (ethene, C2H4), we consider three different methods for axis alignment of a Boltzmann distribution of rotors at 4 K. Specifically, we compare the use of impulsive kick laser pulses having both linear and elliptical polarization to the use of elliptically polarized switched laser pulses. We show that an enhanced degree of field-free three dimensional alignment of ground vibronic state molecules obtains from the use of two orthogonally polarized, time-separated laser pulses. © 2005 The American Physical Society.},
  Affiliation              = {Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom; Steacie Inst. for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ont. K1A 0R6, Canada; Department of Physics, Queen's University, Kingston, Ont. K7L 3N6, Canada},
  Art_number               = {143002},
  Document_type            = {Article},
  Doi                      = {10.1103/PhysRevLett.94.143002},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-18144368547&partnerID=40&md5=fa9d99820fe920e31669f836c16e1cd6}
}

We investigate strategies for field-free three dimensional molecular axis alignment using strong nonresonant laser fields under experimentally realistic conditions. Using the polarizabilites and rotational constants of an asymmetric top rotor molecule (ethene, C2H4), we consider three different methods for axis alignment of a Boltzmann distribution of rotors at 4 K. Specifically, we compare the use of impulsive kick laser pulses having both linear and elliptical polarization to the use of elliptically polarized switched laser pulses. We show that an enhanced degree of field-free three dimensional alignment of ground vibronic state molecules obtains from the use of two orthogonally polarized, time-separated laser pulses. © 2005 The American Physical Society.

@Article{Lausten2003,
  Title                    = {Thermal lensing in pulsed laser amplifiers: An analytical model},
  Author                   = {Lausten, R., Balling, P.},
  Journal                  = {Journal of the Optical Society of America B: Optical Physics},
  Year                     = {2003},
  Number                   = {7},
  Pages                    = {1479-1485},
  Volume                   = {20},

  Abstract                 = {An analytical expression for the thermal-lensing effects in pulsed laser amplifiers is given. The model permits a detailed investigation of the range of parameters where thermal lensing can have severe effects on the operation of crystal-based amplifiers. In particular, the behavior of Ti:sapphire-crystal amplifiers operated at variable repetition rate and pump fluence is discussed. © 2003 Optical Society of America.},
  Affiliation              = {Instituto of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark},
  Document_type            = {Article},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0041809015&partnerID=40&md5=8287ef43b66f07d1db16ef9d84d8f043}
}

An analytical expression for the thermal-lensing effects in pulsed laser amplifiers is given. The model permits a detailed investigation of the range of parameters where thermal lensing can have severe effects on the operation of crystal-based amplifiers. In particular, the behavior of Ti:sapphire-crystal amplifiers operated at variable repetition rate and pump fluence is discussed. © 2003 Optical Society of America.

@Article{Lausten2003a,
  Title                    = {Ultrashort-pulse-laser ablation of metals: Significant changes in ablation rates with depth},
  Author                   = {Lausten, R., Olesen, J.A., Vestentoft, K., Balling, P.},
  Journal                  = {Springer Series in Chemical Physics},
  Year                     = {2003},
  Pages                    = {675-677},
  Volume                   = {71},

  Abstract                 = {Femtosecond-laser ablation rates for a broad range of metals have been investigated and general trends are discussed. A newly developed technique allows the accurate measurement of the ablation rates at all times during the formation of holes.},
  Affiliation              = {Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark},
  Document_type            = {Conference Paper},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0038744435&partnerID=40&md5=f44d6fa9fa0ab162f5c230b3c388945c}
}

Femtosecond-laser ablation rates for a broad range of metals have been investigated and general trends are discussed. A newly developed technique allows the accurate measurement of the ablation rates at all times during the formation of holes.

@Article{Underwood2003,
  Title                    = {Switched wave packets: A route to nonperturbative quantum control},
  Author                   = {Underwood, J.G.a , Spanner, M.a b , Ivanov, M.Yu.a , Mottershead, J.a , Sussman, B.J.a c , Stolow, A.a c },
  Journal                  = {Physical Review Letters},
  Year                     = {2003},
  Number                   = {22},
  Pages                    = {2230011-2230014},
  Volume                   = {90},

  Abstract                 = {Field-free 'switched' wave packets were discussed. The dynamic stark effect and Raman-type coupling were studied. Results showed that field-free switched wave packets contain information about the nature of the strong interaction as well as providing field-free localization.},
  Affiliation              = {Steacie Inst. for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ont., K1A 0R6, Canada; Department of Physics, University of Waterloo, Waterloo, Ont., N2L 3G1, Canada; Department of Physics, Queen's University, Kingston, Ont., K7L 3N6, Canada},
  Document_type            = {Article},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0038792215&partnerID=40&md5=e5098ee6b98853cc7c6a6ef52eeeb07e}
}

Field-free 'switched' wave packets were discussed. The dynamic stark effect and Raman-type coupling were studied. Results showed that field-free switched wave packets contain information about the nature of the strong interaction as well as providing field-free localization.

@Article{Lausten2001,
  Title                    = {On-the-fly depth profiling during ablation with ultrashort laser pulses: A tool for accurate micromachining and laser surgery},
  Author                   = {Lausten, R., Bailing, P.},
  Journal                  = {Applied Physics Letters},
  Year                     = {2001},
  Number                   = {6},
  Pages                    = {884-886},
  Volume                   = {79},

  Abstract                 = {A method for accurate depth profiling of a region subjected to ablation with ultrashort laser pulses is demonstrated. Time-gated imaging of the backscattered radiation from the ablation region is performed in a geometry, which allows the depth along a chosen axis on the sample to be determined with a single measurement. The profiling system has a spatial resolution of a few micrometers and applications are promoted by the fact that the measurement is performed with the same pulse that undertakes ablation. This also indicates that the method is inherently suited for in situ on-the-fly measurements. © 2001 American Institute of Physics.},
  Affiliation              = {Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark},
  Document_type            = {Article},
  Doi                      = {10.1063/1.1391404},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0040374394&partnerID=40&md5=d449a09ef2922763b70a31771c1d8651}
}

A method for accurate depth profiling of a region subjected to ablation with ultrashort laser pulses is demonstrated. Time-gated imaging of the backscattered radiation from the ablation region is performed in a geometry, which allows the depth along a chosen axis on the sample to be determined with a single measurement. The profiling system has a spatial resolution of a few micrometers and applications are promoted by the fact that the measurement is performed with the same pulse that undertakes ablation. This also indicates that the method is inherently suited for in situ on-the-fly measurements. © 2001 American Institute of Physics.

@Article{Korolev2000,
  Title                    = {A technique for habit classification of cloud particles},
  Author                   = {Korolev, A., Sussman, B.},
  Journal                  = {Journal of Atmospheric and Oceanic Technology},
  Year                     = {2000},
  Number                   = {8},
  Pages                    = {1048-1057},
  Volume                   = {17},

  Abstract                 = {A new algorithm was developed to classify populations of binary (black and white) images of cloud particles collected with Particle Measuring Systems (PMS) Optical Array Probes (OAPA). The algorithm classifies images into four habit categories: 'spheres,' 'irregulars,' 'needles,' and 'dendrites.' The present algorithm derives the particle habits from an analysis of dimensionless ratios of simple geometrical measures such as the x and y dimensions, perimeter, and image area. For an ensemble of images containing a mixture of different habits, the distribution of a particular ratio will be a linear superposition of basis distributions of ratios of the individual habits. The fraction of each habit in the ensemble is found by solving the inverse problem. One of the advantages of the suggested scheme is that it provides recognition analysis of both 'complete' and 'partial' images, that is, images that are completely or partially contained within the sample area of the probe. The ability to process 'partial' images improves the statistics of the recognition by approximately 50% when compared with retrievals that use 'complete' images only. The details of this algorithm are discussed in this study.},
  Affiliation              = {Cloud Physics Research Division, Meteorological Service of Canada, 4905 Dufferin Street, Downsview, Ont. M3H 5T4, Canada},
  Document_type            = {Article},
  Source                   = {Scopus},
  Timestamp                = {2016.03.02},
  Url                      = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0033760552&partnerID=40&md5=841182cd8d5459824cfc97c74712f84d}
}

A new algorithm was developed to classify populations of binary (black and white) images of cloud particles collected with Particle Measuring Systems (PMS) Optical Array Probes (OAPA). The algorithm classifies images into four habit categories: 'spheres,' 'irregulars,' 'needles,' and 'dendrites.' The present algorithm derives the particle habits from an analysis of dimensionless ratios of simple geometrical measures such as the x and y dimensions, perimeter, and image area. For an ensemble of images containing a mixture of different habits, the distribution of a particular ratio will be a linear superposition of basis distributions of ratios of the individual habits. The fraction of each habit in the ensemble is found by solving the inverse problem. One of the advantages of the suggested scheme is that it provides recognition analysis of both 'complete' and 'partial' images, that is, images that are completely or partially contained within the sample area of the probe. The ability to process 'partial' images improves the statistics of the recognition by approximately 50% when compared with retrievals that use 'complete' images only. The details of this algorithm are discussed in this study.