@article{
 title = {Spectroscopic and Structural Probing of Excited-State Molecular Dynamics with Time-Resolved Photoelectron Spectroscopy and Ultrafast Electron Diffraction},
 type = {article},
 year = {2020},
 pages = {021016},
 volume = {10},
 websites = {https://link.aps.org/doi/10.1103/PhysRevX.10.021016},
 month = {4},
 publisher = {American Physical Society},
 day = {22},
 id = {a28655e6-9729-3af5-9c62-fa91e98b249a},
 created = {2020-04-23T12:29:38.727Z},
 accessed = {2020-04-23},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2020-04-23T12:30:05.315Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 bibtype = {article},
 author = {Liu, Yusong and Horton, Spencer L. and Yang, Jie and Nunes, J. Pedro F. and Shen, Xiaozhe and Wolf, Thomas J. A. and Forbes, Ruaridh and Cheng, Chuan and Moore, Bryan and Centurion, Martin and Hegazy, Kareem and Li, Renkai and Lin, Ming-Fu and Stolow, Albert and Hockett, Paul and Rozgonyi, Tamás and Marquetand, Philipp and Wang, Xijie and Weinacht, Thomas},
 doi = {10.1103/PhysRevX.10.021016},
 journal = {Physical Review X},
 number = {2}
}

@article{
 title = {Multidimensional quantum-enhanced target detection via spectrotemporal-correlation measurements},
 type = {article},
 year = {2020},
 pages = {053808},
 volume = {101},
 websites = {http://arxiv.org/abs/1909.09664,https://link.aps.org/doi/10.1103/PhysRevA.101.053808},
 month = {5},
 publisher = {American Physical Society},
 day = {4},
 id = {40ba017e-ba9c-3638-9795-2a7566df3219},
 created = {2020-05-06T12:24:17.452Z},
 accessed = {2020-04-23},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2020-05-06T12:24:17.452Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 private_publication = {false},
 abstract = {In this work we investigate quantum-enhanced target detection in the presence of large background noise using multidimensional quantum correlations between photon pairs generated through spontaneous parametric down-conversion. Until now similar experiments have only utilized one of the photon pairs' many degrees of freedom such as temporal correlations and photon number correlations. Here, we utilized both temporal and spectral correlations of the photon pairs and achieved over an order of magnitude reduction to the background noise and in turn significant reduction to data acquisition time when compared to utilizing only temporal modes. We believe this work represents an important step in realizing a practical, real-time quantum-enhanced target detection system. The demonstrated technique will also be of importance in many other quantum sensing applications and quantum communications.},
 bibtype = {article},
 author = {Zhang, Yingwen and England, Duncan and Nomerotski, Andrei and Svihra, Peter and Ferrante, Steven and Hockett, Paul and Sussman, Benjamin},
 doi = {10.1103/PhysRevA.101.053808},
 journal = {Physical Review A},
 number = {5}
}

In this work we investigate quantum-enhanced target detection in the presence of large background noise using multidimensional quantum correlations between photon pairs generated through spontaneous parametric down-conversion. Until now similar experiments have only utilized one of the photon pairs' many degrees of freedom such as temporal correlations and photon number correlations. Here, we utilized both temporal and spectral correlations of the photon pairs and achieved over an order of magnitude reduction to the background noise and in turn significant reduction to data acquisition time when compared to utilizing only temporal modes. We believe this work represents an important step in realizing a practical, real-time quantum-enhanced target detection system. The demonstrated technique will also be of importance in many other quantum sensing applications and quantum communications.

@article{
 title = {Photoelectron angular distributions from resonant two-photon ionisation of adiabatically aligned naphthalene and aniline molecules},
 type = {article},
 year = {2020},
 keywords = {Photoelectron,images,multiphoton ionisation,strong-field alignment},
 id = {f54f3f59-1c19-350e-99f9-7f7144e2b916},
 created = {2020-10-31T23:59:00.000Z},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2020-11-03T12:32:12.631Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2020 Informa UK Limited, trading as Taylor  &  Francis Group. Photoelectron images have been measured following the ionisation of aligned distributions of gas phase naphthalene and aniline molecules. Alignment in the adiabatic regime was achieved by interaction with a 100 ps infrared laser pulse, with ionisation achieved in a two-photon resonant scheme using a low intensity UV pulse of ∼6 ps duration. The resulting images are found to exhibit anisotropy that increases when the alignment pulse is present, with the aniline PADs peaking along the polarisation vector of the ionising light and the naphthalene PADs developing a characteristic four-lobed structure. Photoelectron angular distributions (PADs) that result from the ionisation of unaligned and fully aligned distributions of molecules are calculated using the ePolyScat ab initio suite and converted into two-dimensional photoelectron images. In the case of naphthalene excellent agreement is observed between experiment and the simulation for the fully aligned distribution, showing that the alignment step allows us to probe the molecular frame, but in the case of aniline it is clear that additional processes occur following the one-photon resonant step.},
 bibtype = {article},
 author = {Arlt, J. and Singh, D.P. and Thompson, J.O.F. and Chatterley, A.S. and Hockett, P. and Stapelfeldt, H. and Reid, K.L.},
 doi = {10.1080/00268976.2020.1836411},
 journal = {Molecular Physics}
}

© 2020 Informa UK Limited, trading as Taylor & Francis Group. Photoelectron images have been measured following the ionisation of aligned distributions of gas phase naphthalene and aniline molecules. Alignment in the adiabatic regime was achieved by interaction with a 100 ps infrared laser pulse, with ionisation achieved in a two-photon resonant scheme using a low intensity UV pulse of ∼6 ps duration. The resulting images are found to exhibit anisotropy that increases when the alignment pulse is present, with the aniline PADs peaking along the polarisation vector of the ionising light and the naphthalene PADs developing a characteristic four-lobed structure. Photoelectron angular distributions (PADs) that result from the ionisation of unaligned and fully aligned distributions of molecules are calculated using the ePolyScat ab initio suite and converted into two-dimensional photoelectron images. In the case of naphthalene excellent agreement is observed between experiment and the simulation for the fully aligned distribution, showing that the alignment step allows us to probe the molecular frame, but in the case of aniline it is clear that additional processes occur following the one-photon resonant step.

@misc{
 title = {Molecular frame photoelectron angular distributions in polyatomic molecules from lab frame coherent rotational wavepacket evolution},
 type = {misc},
 year = {2020},
 source = {arXiv},
 id = {e9814f6e-2026-36c8-a021-622afd1d8aba},
 created = {2021-02-01T23:59:00.000Z},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2021-02-15T12:08:08.959Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2020, CC BY. The application of a matrix-based reconstruction protocol for obtaining Molecular Frame (MF) photoelectron angular distributions (MFPADs) from laboratory frame LF measurements (LFPADs) is explored. Similarly to other recent works on the topic of MF reconstruction, this protocol makes use of time-resolved LF measurements, in which a rotational wavepacket is prepared and probed via photoionization, followed by a numerical reconstruction routine; however, in contrast to other methodologies, the protocol developed herein does not require determination of photoionization matrix elements, and consequently takes a relatively simple numerical form (matrix transform making use of the Moore-Penrose inverse). Significantly, the simplicity allows application of the method to the successful reconstruction of MFPADs for polyatomic molecules. The scheme is demonstrated numerically for two realistic cases, N2 and C2H4. The new technique is expected to be generally applicable for a range of MF reconstruction problems involving photoionization of polyatomic molecules.},
 bibtype = {misc},
 author = {Gregory, M. and Hockett, P. and Stolow, A. and Makhija, V.}
}

© 2020, CC BY. The application of a matrix-based reconstruction protocol for obtaining Molecular Frame (MF) photoelectron angular distributions (MFPADs) from laboratory frame LF measurements (LFPADs) is explored. Similarly to other recent works on the topic of MF reconstruction, this protocol makes use of time-resolved LF measurements, in which a rotational wavepacket is prepared and probed via photoionization, followed by a numerical reconstruction routine; however, in contrast to other methodologies, the protocol developed herein does not require determination of photoionization matrix elements, and consequently takes a relatively simple numerical form (matrix transform making use of the Moore-Penrose inverse). Significantly, the simplicity allows application of the method to the successful reconstruction of MFPADs for polyatomic molecules. The scheme is demonstrated numerically for two realistic cases, N2 and C2H4. The new technique is expected to be generally applicable for a range of MF reconstruction problems involving photoionization of polyatomic molecules.

@misc{
 title = {ePolyScat Collected Results (OSF) - aniline},
 type = {misc},
 year = {2019},
 websites = {https://osf.io/psjxt/wiki/aniline/},
 id = {a48d9af1-9406-3580-abff-82ec1788918b},
 created = {2019-10-30T13:54:18.972Z},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2019-10-30T13:54:18.972Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 private_publication = {false},
 bibtype = {misc},
 author = {Hockett, Paul},
 doi = {10.17605/OSF.IO/PSJXT}
}

@article{
 title = {Multidimensional quantum-enhanced target detection via spectro-temporal correlation measurements},
 type = {article},
 year = {2019},
 websites = {http://arxiv.org/abs/1909.09664},
 month = {9},
 day = {20},
 id = {30f0f6bc-17ee-329e-bf85-1c831ea031dc},
 created = {2020-04-23T12:30:47.303Z},
 accessed = {2020-04-23},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2020-04-23T12:30:59.732Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {In this work we investigate quantum-enhanced target detection in the presence of large background noise using multidimensional quantum correlations between photon pairs generated through spontaneous parametric down-conversion. Until now similar experiments have only utilized one of the photon pairs' many degrees of freedom such as temporal correlations and photon number correlations. Here, we utilized both temporal and spectral correlations of the photon pairs and achieved over an order of magnitude reduction to the background noise and in turn significant reduction to data acquisition time when compared to utilizing only temporal modes. We believe this work represents an important step in realizing a practical, real-time quantum-enhanced target detection system. The demonstrated technique will also be of importance in many other quantum sensing applications and quantum communications.},
 bibtype = {article},
 author = {Zhang, Yingwen and England, Duncan and Nomerotski, Andrei and Svihra, Peter and Ferrante, Steven and Hockett, Paul and Sussman, Benjamin}
}

In this work we investigate quantum-enhanced target detection in the presence of large background noise using multidimensional quantum correlations between photon pairs generated through spontaneous parametric down-conversion. Until now similar experiments have only utilized one of the photon pairs' many degrees of freedom such as temporal correlations and photon number correlations. Here, we utilized both temporal and spectral correlations of the photon pairs and achieved over an order of magnitude reduction to the background noise and in turn significant reduction to data acquisition time when compared to utilizing only temporal modes. We believe this work represents an important step in realizing a practical, real-time quantum-enhanced target detection system. The demonstrated technique will also be of importance in many other quantum sensing applications and quantum communications.

@article{
 title = {Excited state dynamics of CH <inf>2</inf> I <inf>2</inf> and CH <inf>2</inf> BrI studied with UV pump VUV probe photoelectron spectroscopy},
 type = {article},
 year = {2019},
 volume = {150},
 id = {67d8cbc9-a97f-3ae5-b967-ff29e197b796},
 created = {2019-05-21T23:59:00.000Z},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2020-12-21T11:04:46.705Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {false},
 hidden = {false},
 private_publication = {false},
 abstract = {© 2019 Author(s).  We compare the excited state dynamics of diiodomethane (CH 2 I 2 ) and bromoiodomethane (CH 2 BrI) using time resolved photoelectron spectroscopy. A 4.65 eV UV pump pulse launches a dissociative wave packet on excited states of both molecules and the ensuing dynamics are probed via photoionization using a 7.75 eV probe pulse. The resulting photoelectrons are measured with the velocity map imaging technique for each pump-probe delay. Our measurements highlight differences in the dynamics for the two molecules, which are interpreted with high-level ab initio molecular dynamics (trajectory surface hopping) calculations. Our analysis allows us to associate features in the photoelectron spectrum with different portions of the excited state wave packet represented by different trajectories. The excited state dynamics in bromoiodomethane are simple and can be described in terms of direct dissociation along the C-I coordinate, whereas the dynamics in diiodomethane involve internal conversion and motion along multiple dimensions.},
 bibtype = {article},
 author = {Horton, S.L. and Liu, Y. and Forbes, R. and Makhija, V. and Lausten, R. and Stolow, A. and Hockett, P. and Marquetand, P. and Rozgonyi, T. and Weinacht, T.},
 doi = {10.1063/1.5086665},
 journal = {Journal of Chemical Physics},
 number = {17}
}

© 2019 Author(s). We compare the excited state dynamics of diiodomethane (CH 2 I 2 ) and bromoiodomethane (CH 2 BrI) using time resolved photoelectron spectroscopy. A 4.65 eV UV pump pulse launches a dissociative wave packet on excited states of both molecules and the ensuing dynamics are probed via photoionization using a 7.75 eV probe pulse. The resulting photoelectrons are measured with the velocity map imaging technique for each pump-probe delay. Our measurements highlight differences in the dynamics for the two molecules, which are interpreted with high-level ab initio molecular dynamics (trajectory surface hopping) calculations. Our analysis allows us to associate features in the photoelectron spectrum with different portions of the excited state wave packet represented by different trajectories. The excited state dynamics in bromoiodomethane are simple and can be described in terms of direct dissociation along the C-I coordinate, whereas the dynamics in diiodomethane involve internal conversion and motion along multiple dimensions.

@article{
 title = {Quantum-beat photoelectron-imaging spectroscopy of Xe in the VUV},
 type = {article},
 year = {2018},
 pages = {063417},
 volume = {97},
 websites = {http://arxiv.org/abs/1803.01081,https://link.aps.org/doi/10.1103/PhysRevA.97.063417},
 month = {6},
 day = {22},
 id = {56754a4b-735b-3184-b577-cafe8ad24a4b},
 created = {2018-04-05T22:23:52.736Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2018-09-10T15:09:20.690Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Forbes2018},
 private_publication = {false},
 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 $5p^5(^2P^\circ_1/2)6s~^2[1/2]^\circ_1$ 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.},
 bibtype = {article},
 author = {Forbes, Ruaridh and Makhija, Varun and Underwood, Jonathan G. and Stolow, Albert and Wilkinson, Iain and Hockett, Paul and Lausten, Rune},
 doi = {10.1103/PhysRevA.97.063417},
 journal = {Physical Review A},
 number = {6}
}

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 $5p^5(^2P^\circ_1/2)6s~^2[1/2]^\circ_1$ 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{
 title = {Quantum Metrology with Photoelectrons, Volume 2 Applications and advances},
 type = {book},
 year = {2018},
 websites = {https://osf.io/q2v3g,http://iopscience.iop.org/book/978-1-6817-4688-3},
 publisher = {IOP Publishing},
 id = {fcee9b1e-4139-35cb-b2e0-6b4c76aa63a4},
 created = {2018-04-30T14:59:46.238Z},
 accessed = {2018-04-26},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2019-01-25T15:04:00.817Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2018QMVol2},
 private_publication = {false},
 bibtype = {book},
 author = {Hockett, Paul},
 doi = {10.1088/978-1-6817-4688-3}
}

@book{
 title = {Quantum Metrology with Photoelectrons, Volume 1 Foundations},
 type = {book},
 year = {2018},
 websites = {https://osf.io/q2v3g,http://iopscience.iop.org/book/978-1-6817-4684-5},
 publisher = {IOP Publishing},
 id = {2f5a384e-2e3e-3da2-a4da-5f2aa803a529},
 created = {2018-04-30T14:59:46.257Z},
 accessed = {2018-04-26},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2019-01-25T15:04:01.044Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2018QMVol1},
 private_publication = {false},
 bibtype = {book},
 author = {Hockett, Paul},
 doi = {10.1088/978-1-6817-4684-5}
}

@article{
 title = {Monitoring non-adiabatic dynamics in CS2 with time- and energy-resolved photoelectron spectra of wavepackets},
 type = {article},
 year = {2017},
 websites = {http://dx.doi.org/10.1016/j.cplett.2017.02.014},
 publisher = {Elsevier B.V.},
 id = {ee73eb01-36f2-3b17-a821-faa721b456c5},
 created = {2017-03-22T14:07:03.249Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-09-25T00:12:12.300Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Wang2017},
 folder_uuids = {c54e4293-56e6-448b-a46b-1e8ce8d574b6},
 private_publication = {false},
 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.},
 bibtype = {article},
 author = {Wang, Kwanghsi and McKoy, Vincent and Hockett, Paul and Stolow, Albert and Schuurman, Michael S.},
 doi = {10.1016/j.cplett.2017.02.014},
 journal = {Chemical Physics Letters}
}

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.

@article{
 title = {Reply to Comment on ‘Time delays in molecular photoionization’},
 type = {article},
 year = {2017},
 pages = {078003},
 volume = {50},
 websites = {http://arxiv.org/abs/1611.09352,http://stacks.iop.org/0953-4075/50/i=7/a=078003?key=crossref.2c8876d98918846013e0dfe413ae293d},
 month = {4},
 publisher = {IOP Publishing},
 day = {14},
 id = {de644c69-f6a3-379f-beff-824219a97a68},
 created = {2017-03-22T14:07:03.393Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-04-03T14:01:37.590Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2017},
 private_publication = {false},
 abstract = {In a recent article by P. Hockett \textitet al., time delays arising in the context of molecular single-photon ionization are investigated from a theoretical point of view. We argue that one of the central equations derived in the paper is incorrect and present a reformulation that is consistent with the established treatment of angle-dependent scattering delays.},
 bibtype = {article},
 author = {Hockett, P and Frumker, E and Villeneuve, D M and Corkum, P B},
 doi = {10.1088/1361-6455/aa620c},
 journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
 number = {7}
}

In a recent article by P. Hockett \textitet al., time delays arising in the context of molecular single-photon ionization are investigated from a theoretical point of view. We argue that one of the central equations derived in the paper is incorrect and present a reformulation that is consistent with the established treatment of angle-dependent scattering delays.

@article{
 title = {Time-resolved multi-mass ion imaging: Femtosecond UV-VUV pump-probe spectroscopy with the PImMS camera},
 type = {article},
 year = {2017},
 pages = {013911},
 volume = {147},
 websites = {http://arxiv.org/abs/1702.00744,http://dx.doi.org/10.1063/1.4978923,http://aip.scitation.org/doi/10.1063/1.4978923},
 month = {7},
 day = {7},
 id = {af03cec4-89e4-3d57-9aee-f1b4b5adbb81},
 created = {2017-04-05T01:25:09.689Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2018-10-19T14:55:24.175Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Forbes2017},
 folder_uuids = {8c03ef1b-cd23-4d48-b9aa-8134c3f4c817},
 private_publication = {false},
 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.},
 bibtype = {article},
 author = {Forbes, Ruaridh and Makhija, Varun and Veyrinas, Kévin 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},
 doi = {10.1063/1.4978923},
 journal = {The Journal of Chemical Physics},
 number = {1}
}

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{
 title = {Coherent imaging of an attosecond electron wave packet},
 type = {article},
 year = {2017},
 pages = {1150-1153},
 volume = {356},
 websites = {http://www.sciencemag.org/lookup/doi/10.1126/science.aam8393},
 month = {6},
 day = {16},
 id = {79f000f5-75bc-3e04-955d-dad9f77e6a95},
 created = {2017-06-16T15:33:33.474Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-12-05T21:44:26.440Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Villeneuve2017a},
 private_publication = {false},
 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 ' ¼ 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.},
 bibtype = {article},
 author = {Villeneuve, D M and Hockett, Paul and Vrakking, M J J and Niikura, Hiromichi},
 doi = {10.1126/science.aam8393},
 journal = {Science},
 number = {6343}
}

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 ' ¼ 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{
 title = {Angle-resolved RABBITT: theory and numerics},
 type = {article},
 year = {2017},
 keywords = {angle-resolved,atto,photoelectron spectroscopy,photoionization,ultrafast},
 pages = {154002},
 volume = {50},
 websites = {http://stacks.iop.org/0953-4075/50/i=15/a=154002?key=crossref.5d6778123ace5e660772ac4533b801a0},
 month = {8},
 day = {14},
 id = {0a85c154-1e06-3dca-9704-13201c8b4eb8},
 created = {2017-08-11T10:04:50.528Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-09-20T17:00:44.985Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2017a},
 private_publication = {false},
 abstract = {© 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.},
 bibtype = {article},
 author = {Hockett, Paul},
 doi = {10.1088/1361-6455/aa7887},
 journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
 number = {15}
}

© 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{
 title = {Molecular Frame Reconstruction Using Time-Domain Photoionization Interferometry},
 type = {article},
 year = {2017},
 pages = {083401},
 volume = {119},
 websites = {https://link.aps.org/doi/10.1103/PhysRevLett.119.083401},
 month = {8},
 publisher = {American Physical Society},
 day = {22},
 id = {35e1041c-22ae-31ac-935b-38ad849b8cd0},
 created = {2017-08-24T13:09:48.646Z},
 accessed = {2017-08-24},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2018-04-05T22:23:53.168Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Marceau2017},
 folder_uuids = {ed2dc36d-e094-40d7-881f-780b861d86ad},
 private_publication = {false},
 bibtype = {article},
 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},
 doi = {10.1103/PhysRevLett.119.083401},
 journal = {Physical Review Letters},
 number = {8}
}

@article{
 title = {Time delay in molecular photoionization},
 type = {article},
 year = {2016},
 keywords = {Wigner delay,angle-resolved,appear in colour only,attosecond,in the online journal,molecular,photoionization,some fi gures may,wigner delay},
 pages = {095602},
 volume = {49},
 websites = {http://dx.doi.org/10.1088/0953-4075/49/9/095602},
 month = {5},
 publisher = {IOP Publishing},
 day = {14},
 id = {2aee64a8-0f59-34d9-9c1b-3d1198f387c7},
 created = {2016-05-27T17:02:22.000Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-03-14T07:19:21.662Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2015c},
 folder_uuids = {b43b7ea8-801c-4caf-afba-a9eb47977a94,84ae8bae-f6cb-40c9-9fc4-1a2115bebfa2,961ee46f-bc30-4d3b-9b8e-d694375f8791},
 private_publication = {false},
 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.},
 bibtype = {article},
 author = {Hockett, Paul and Frumker, Eugene and Villeneuve, David M and Corkum, Paul B},
 doi = {10.1088/0953-4075/49/9/095602},
 journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
 number = {9}
}

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.

@misc{
 title = {ePSproc: Post-processing for ePolyScat (v1.0.0)},
 type = {misc},
 year = {2016},
 websites = {https://figshare.com/articles/ePSproc_Post-processing_for_ePolyScat_v1_0_0_/3545639,https://github.com/phockett/ePSproc},
 id = {51a6f094-89a6-3f17-b1a9-b9e172f38833},
 created = {2016-10-09T14:52:17.000Z},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2019-09-03T19:45:56.050Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2016a},
 folder_uuids = {84ae8bae-f6cb-40c9-9fc4-1a2115bebfa2},
 private_publication = {false},
 bibtype = {misc},
 author = {Hockett, Paul},
 doi = {10.6084/m9.figshare.3545639.v1}
}

@article{
 title = {ePSproc: Post-processing suite for ePolyScat electron-molecule scattering calculations},
 type = {article},
 year = {2016},
 websites = {https://www.authorea.com/users/71114/articles/122402/_show_article},
 id = {4822eee5-28fc-3e19-bd6b-1cea32c287f2},
 created = {2016-10-09T15:06:13.000Z},
 file_attached = {false},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-05-23T14:17:09.137Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2016c},
 folder_uuids = {a330a250-356c-4ed3-8faf-f5b53f3ad19f,84ae8bae-f6cb-40c9-9fc4-1a2115bebfa2},
 private_publication = {false},
 bibtype = {article},
 author = {Hockett, Paul},
 doi = {10.6084/m9.figshare.3545639},
 journal = {Authorea}
}

@article{
 title = {Response to 'Comment on "Time delays in molecular photoionization"': Extended Discussion & Technical Notes},
 type = {article},
 year = {2016},
 volume = {1612.00481},
 websites = {http://arxiv.org/abs/1612.00481},
 month = {12},
 day = {1},
 id = {85614ef7-7782-348e-bcd2-9f5b90de4196},
 created = {2017-02-12T14:43:37.000Z},
 accessed = {2017-02-12},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-03-14T07:19:21.662Z},
 read = {false},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2016},
 folder_uuids = {84ae8bae-f6cb-40c9-9fc4-1a2115bebfa2},
 private_publication = {false},
 abstract = {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.},
 bibtype = {article},
 author = {Hockett, Paul and Frumker, Eugene},
 journal = {arXiv}
}

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{
 title = {Augmented Reality with Hololens: Experiential Architectures Embedded in the Real World},
 type = {article},
 year = {2016},
 pages = {1-10},
 websites = {http://arxiv.org/abs/1610.04281},
 month = {10},
 day = {13},
 id = {80e705d3-3156-300e-ba7b-87fa3a6a3b83},
 created = {2017-04-26T11:18:32.074Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2018-02-12T01:27:22.559Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2016d},
 private_publication = {false},
 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.},
 bibtype = {article},
 author = {Hockett, Paul and Ingleby, Tim},
 doi = {10.22541/au.148821660.05483993},
 journal = {arXiv}
}

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{
 title = {Maximum-information photoelectron metrology},
 type = {article},
 year = {2015},
 pages = {013412},
 volume = {92},
 websites = {http://link.aps.org/doi/10.1103/PhysRevA.92.013412},
 month = {7},
 day = {13},
 id = {2a22d449-4f58-3a05-8be8-7f061bcb0863},
 created = {2014-10-15T15:38:44.000Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-03-14T07:19:21.662Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2015b},
 folder_uuids = {b43b7ea8-801c-4caf-afba-a9eb47977a94,88db0d4c-ac6d-4dc5-a7ba-0b26c0501375,07b83624-8dbb-4b33-b379-7f5f6a5285dd,961ee46f-bc30-4d3b-9b8e-d694375f8791},
 private_publication = {false},
 bibtype = {article},
 author = {Hockett, Paul and Lux, Christian and Wollenhaupt, Matthias and Baumert, Thomas},
 doi = {10.1103/PhysRevA.92.013412},
 journal = {Physical Review A},
 number = {1}
}

@article{
 title = {General phenomenology of ionization from aligned molecular ensembles},
 type = {article},
 year = {2015},
 keywords = {ionization,molecular alignment,multiphoton processes,photoelectron angular distributions},
 pages = {023069},
 volume = {17},
 websites = {http://dx.doi.org/10.1088/1367-2630/17/2/023069,http://stacks.iop.org/1367-2630/17/i=2/a=023069?key=crossref.bdbb6f53e1f801f11c6bfeca01330fde},
 month = {2},
 publisher = {IOP Publishing},
 day = {24},
 id = {c9824819-ee12-3444-82f1-05fa347f1f48},
 created = {2015-02-25T15:30:58.000Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-09-11T16:33:46.756Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2015},
 folder_uuids = {a330a250-356c-4ed3-8faf-f5b53f3ad19f},
 private_publication = {false},
 bibtype = {article},
 author = {Hockett, Paul},
 doi = {10.1088/1367-2630/17/2/023069},
 journal = {New Journal of Physics},
 number = {2}
}

@article{
 title = {Nonclassical correlations between terahertz-bandwidth photons mediated by rotational quanta in hydrogen molecules},
 type = {article},
 year = {2015},
 keywords = {Coherent optical effects,Raman,Scattering,Ultrafast nonlinear optics},
 pages = {922},
 volume = {40},
 websites = {http://ol.osa.org/abstract.cfm?URI=ol-40-6-922},
 month = {3},
 publisher = {OSA},
 day = {4},
 id = {a897258d-0546-3fb0-8839-f68942403274},
 created = {2015-03-03T20:53:09.000Z},
 accessed = {2015-03-03},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2019-09-12T22:45:58.121Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Bustard2015},
 short_title = {Opt. Lett.},
 private_publication = {false},
 abstract = {Quantum photonics offers much promise for the development of new technologies. The ability to control the interaction of light and matter at the level of single quantum excitations is a prerequisite for the construction of potentially powerful devices. Here we use the rotational levels of a room temperature ensemble of hydrogen molecules to couple two distinct optical modes at the single photon level using femtosecond pulses with 2 THz bandwidth. We observe photon correlations that violate a Cauchy–Schwarz inequality, thereby verifying the creation of a nonclassical state. This work demonstrates the rich potential of molecules for use in ultrafast quantum photonic devices.},
 bibtype = {article},
 author = {Bustard, Philip J. and Erskine, Jennifer and England, Duncan G. and Nunn, Josh and Hockett, Paul and Lausten, Rune and Spanner, Michael and Sussman, Benjamin J.},
 doi = {10.1364/OL.40.000922},
 journal = {Optics Letters},
 number = {6}
}

Quantum photonics offers much promise for the development of new technologies. The ability to control the interaction of light and matter at the level of single quantum excitations is a prerequisite for the construction of potentially powerful devices. Here we use the rotational levels of a room temperature ensemble of hydrogen molecules to couple two distinct optical modes at the single photon level using femtosecond pulses with 2 THz bandwidth. We observe photon correlations that violate a Cauchy–Schwarz inequality, thereby verifying the creation of a nonclassical state. This work demonstrates the rich potential of molecules for use in ultrafast quantum photonic devices.

@article{
 title = {Complete photoionization experiments via ultrafast coherent control with polarization multiplexing. II. Numerics and analysis methodologies},
 type = {article},
 year = {2015},
 pages = {013411},
 volume = {92},
 websites = {http://link.aps.org/doi/10.1103/PhysRevA.92.013411},
 month = {7},
 day = {13},
 id = {d2eafa33-b453-3aa6-87b3-286703112ec3},
 created = {2015-03-04T20:30:11.000Z},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-03-14T07:19:21.662Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2015a},
 folder_uuids = {a330a250-356c-4ed3-8faf-f5b53f3ad19f,b43b7ea8-801c-4caf-afba-a9eb47977a94,2b82d7f3-0d83-4007-a434-24e18782c065,07b83624-8dbb-4b33-b379-7f5f6a5285dd,961ee46f-bc30-4d3b-9b8e-d694375f8791},
 private_publication = {false},
 bibtype = {article},
 author = {Hockett, Paul and Wollenhaupt, Matthias and Lux, Christian and Baumert, Thomas},
 doi = {10.1103/PhysRevA.92.013411},
 journal = {Physical Review A},
 number = {1}
}

@article{
 title = {Coherent control of photoelectron wavepacket angular interferograms},
 type = {article},
 year = {2015},
 pages = {214004},
 volume = {48},
 websites = {http://stacks.iop.org/0953-4075/48/i=21/a=214004?key=crossref.8f534585af9180a499934cb25c9994c1},
 month = {11},
 day = {14},
 id = {8beae1f9-f665-3097-ab29-e57ba8c54241},
 created = {2015-09-23T18:34:03.000Z},
 accessed = {2015-09-23},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-03-14T07:19:21.662Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2015d},
 folder_uuids = {b25ed999-7fa6-4f08-85d5-c381220e58e4},
 private_publication = {false},
 bibtype = {article},
 author = {Hockett, P and Wollenhaupt, M and Baumert, T},
 doi = {10.1088/0953-4075/48/21/214004},
 journal = {Journal of Physics B: Atomic, Molecular and Optical Physics},
 number = {21}
}

@article{
 title = {Time-Resolved Photoelectron Spectra of CS2: Dynamics at Conical Intersections},
 type = {article},
 year = {2014},
 pages = {113007},
 volume = {112},
 websites = {http://link.aps.org/doi/10.1103/PhysRevLett.112.113007},
 month = {3},
 day = {21},
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 author = {Wang, Kwanghsi and McKoy, Vincent and Hockett, Paul and Schuurman, Michael S.},
 doi = {10.1103/PhysRevLett.112.113007},
 journal = {Physical Review Letters},
 number = {11}
}

@article{
 title = {Complete Photoionization Experiments via Ultrafast Coherent Control with Polarization Multiplexing},
 type = {article},
 year = {2014},
 pages = {223001},
 volume = {112},
 websites = {http://link.aps.org/doi/10.1103/PhysRevLett.112.223001},
 month = {6},
 day = {5},
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 author = {Hockett, P. and Wollenhaupt, M. and Lux, C. and Baumert, T.},
 doi = {10.1103/PhysRevLett.112.223001},
 journal = {Physical Review Letters},
 number = {22}
}

@misc{
 title = {Quantum Dynamical Imaging via Time-resolved Photoelectron Interferometry: Beyond a Phenomenological Imaging of Molecular Dynamics, DOI: 10.6084/m9.figshare.3580734},
 type = {misc},
 year = {2014},
 websites = {https://doi.org/10.6084/m9.figshare.3580734},
 publisher = {Figshare},
 id = {bbbbd80a-c41c-372f-a3c0-6f5cc85dc631},
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 author = {Hockett, Paul},
 doi = {10.6084/m9.figshare.3580734}
}

@article{
 title = {Probing ultrafast dynamics with time-resolved multi-dimensional coincidence imaging: butadiene},
 type = {article},
 year = {2013},
 keywords = {TRPADs,TRPES,coincidence imaging},
 pages = {1409-1425},
 volume = {60},
 websites = {http://www.tandfonline.com/doi/abs/10.1080/09500340.2013.801525},
 month = {10},
 day = {7},
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 author = {Hockett, Paul and Ripani, Enrico and Rytwinski, Andrew and Stolow, Albert},
 doi = {10.1080/09500340.2013.801525},
 journal = {Journal of Modern Optics},
 number = {17}
}

@article{
 title = {Probing Polar Molecules with High Harmonic Spectroscopy},
 type = {article},
 year = {2012},
 pages = {233904},
 volume = {109},
 websites = {http://link.aps.org/doi/10.1103/PhysRevLett.109.233904},
 month = {12},
 publisher = {American Physical Society},
 day = {4},
 id = {3895ab3c-5e26-3edc-ab56-c5379719d55a},
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 read = {true},
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 hidden = {false},
 citation_key = {Frumker2012},
 short_title = {Phys. Rev. Lett.},
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 private_publication = {false},
 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.},
 bibtype = {article},
 author = {Frumker, E. and Kajumba, N. and Bertrand, J. B. and Wörner, H. J. and Hebeisen, C. T. and Hockett, P. and Spanner, M. and Patchkovskii, S. and Paulus, G. G. and Villeneuve, D. M. and Naumov, A. and Corkum, P. B.},
 doi = {10.1103/PhysRevLett.109.233904},
 journal = {Physical Review Letters},
 number = {23}
}

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.

@article{
 title = {Revealing the Cooper minimum of N_2 by Molecular Frame High-Harmonic Spectroscopy},
 type = {article},
 year = {2012},
 pages = {143001},
 volume = {109},
 websites = {http://link.aps.org/doi/10.1103/PhysRevLett.109.143001},
 month = {10},
 publisher = {American Physical Society},
 day = {4},
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 private_publication = {false},
 abstract = {Molecular frame high-harmonic spectra of aligned N2 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.},
 bibtype = {article},
 author = {Bertrand, J. B. and Wörner, H. J. and Hockett, P. and Villeneuve, D. M. and Corkum, P. B.},
 doi = {10.1103/PhysRevLett.109.143001},
 journal = {Physical Review Letters},
 number = {14}
}

Molecular frame high-harmonic spectra of aligned N2 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.

@inproceedings{
 title = {Attosecond pulse trains generated with oriented molecules},
 type = {inproceedings},
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 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.},
 bibtype = {inproceedings},
 author = {Frumker, E. and Kajumba, N. and Bertrand, J.B. and Worner, H.J. and Hebeisen, C.T. and Hockett, P. and Spanner, M. and Patchkovskii, S. and Paulus, G.G. and Villeneuve, D.M. and Corkum, P.B.},
 booktitle = {2012 Conference on Lasers and Electro-Optics, CLEO 2012}
}

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{
 title = {Erratum: Probing Polar Molecules with High Harmonic Spectroscopy (Physical Review Letters (2012) 109 (233904)},
 type = {article},
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 doi = {10.1103/PhysRevLett.109.249902},
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 number = {24}
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@inproceedings{
 title = {Attosecond pulse trains generated with oriented molecules},
 type = {inproceedings},
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 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. © 2011 Optical Society of America.},
 bibtype = {inproceedings},
 author = {Frumker, E. and Kajumba, N. and Bertrand, J.B. and Worner, H.J. and Hebeisen, C.T. and Hockett, P. and Spanner, M. and Patchkovskii, S. and Paulus, G.G. and Villeneuve, D.M. and Corkum, P.B.},
 booktitle = {Optics InfoBase Conference Papers}
}

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. © 2011 Optical Society of America.

@article{
 title = {Attosecond pulse trains generated with oriented molecules},
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@article{
 title = {Rotational dephasing of symmetric top molecules: Analytic expressions and applications},
 type = {article},
 year = {2011},
 pages = {237-241},
 volume = {517},
 websites = {http://linkinghub.elsevier.com/retrieve/pii/S0009261411013157},
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 journal = {Chemical Physics Letters},
 number = {4-6}
}

@article{
 title = {Time-resolved photoelectron spectroscopy: from wavepackets to observables.},
 type = {article},
 year = {2011},
 pages = {18447-67},
 volume = {13},
 websites = {http://pubs.rsc.org/en/content/articlelanding/2011/cp/c1cp22031d},
 month = {11},
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 private_publication = {false},
 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.},
 bibtype = {article},
 author = {Wu, Guorong and Hockett, Paul and Stolow, Albert},
 doi = {10.1039/c1cp22031d},
 journal = {Physical chemistry chemical physics : PCCP},
 number = {41}
}

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.

@article{
 title = {Time-resolved imaging of purely valence-electron dynamics during a chemical reaction},
 type = {article},
 year = {2011},
 pages = {612-615},
 volume = {7},
 websites = {http://www.nature.com/doifinder/10.1038/nphys1980},
 month = {4},
 day = {17},
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 bibtype = {article},
 author = {Hockett, Paul and Bisgaard, Christer Z. and Clarkin, Owen J. and Stolow, Albert},
 doi = {10.1038/nphys1980},
 journal = {Nature Physics},
 number = {8}
}

@article{
 title = {Photoionization dynamics of ammonia (B(1)E''): dependence on ionizing photon energy and initial vibrational level.},
 type = {article},
 year = {2010},
 keywords = {Ammonia,Ammonia: chemistry,Molecular Dynamics Simulation,Photochemistry,Photons,Quantum Theory,Vibration},
 pages = {11330-6},
 volume = {114},
 websites = {http://dx.doi.org/10.1021/jp104623m},
 month = {10},
 day = {28},
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 citation_key = {Hockett2010a},
 folder_uuids = {961ee46f-bc30-4d3b-9b8e-d694375f8791},
 private_publication = {false},
 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.},
 bibtype = {article},
 author = {Hockett, Paul and Staniforth, Michael and Reid, Katharine L},
 doi = {10.1021/jp104623m},
 journal = {The journal of physical chemistry. A},
 number = {42}
}

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.

@article{
 title = {Controlling the Interference of Multiple Molecular Orbitals in High-Harmonic Generation},
 type = {article},
 year = {2010},
 pages = {233904},
 volume = {104},
 websites = {http://link.aps.org/doi/10.1103/PhysRevLett.104.233904},
 month = {6},
 id = {7f5e43b2-4520-3d6c-9b3c-a9e5406b7b92},
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 bibtype = {article},
 author = {Wörner, H. J. and Bertrand, J. B. and Hockett, P. and Corkum, P. B. and Villeneuve, D. M.},
 doi = {10.1103/PhysRevLett.104.233904},
 journal = {Physical Review Letters},
 number = {23}
}

@article{
 title = {Photoelectron angular distributions from rotationally state-selected NH 3 (B 1 E′′): dependence on ion rotational state and polarization geometry},
 type = {article},
 year = {2010},
 pages = {1045-1054},
 volume = {108},
 websites = {http://www.tandfonline.com/doi/abs/10.1080/00268971003639266},
 month = {4},
 day = {10},
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 author = {Hockett, Paul and Staniforth, Michael and Reid, Katharine L.},
 doi = {10.1080/00268971003639266},
 journal = {Molecular Physics},
 number = {7-9}
}

@article{
 title = {Rotationally Resolved Photoelectron Angular Distributions from a Nonlinear Polyatomic Molecule},
 type = {article},
 year = {2009},
 pages = {253002},
 volume = {102},
 websites = {http://link.aps.org/doi/10.1103/PhysRevLett.102.253002},
 month = {6},
 id = {e5319134-f2fe-32cd-833a-1c51bb3d4741},
 created = {2012-07-20T19:12:33.000Z},
 accessed = {2014-04-14},
 file_attached = {true},
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 last_modified = {2017-03-14T07:19:21.662Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2009},
 folder_uuids = {a330a250-356c-4ed3-8faf-f5b53f3ad19f,b43b7ea8-801c-4caf-afba-a9eb47977a94,88db0d4c-ac6d-4dc5-a7ba-0b26c0501375,2b82d7f3-0d83-4007-a434-24e18782c065,3af1283f-8b49-420d-bc7e-45c8676334e3,cb17f54b-2fed-4a3d-b6a3-53350fcfa339,961ee46f-bc30-4d3b-9b8e-d694375f8791},
 private_publication = {false},
 bibtype = {article},
 author = {Hockett, Paul and Staniforth, Michael and Reid, Katharine L. and Townsend, Dave},
 doi = {10.1103/PhysRevLett.102.253002},
 journal = {Physical Review Letters},
 number = {25}
}

@phdthesis{
 title = {Photoionization dynamics of polyatomic molecules},
 type = {phdthesis},
 year = {2009},
 websites = {http://eprints.nottingham.ac.uk/10857/},
 institution = {University of Nottingham},
 department = {School of Chemistry},
 id = {5754e748-3a0b-34d4-8c8d-532096ecb35b},
 created = {2017-05-15T13:33:07.627Z},
 accessed = {2017-05-15},
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 last_modified = {2017-08-16T14:00:10.545Z},
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 starred = {false},
 authored = {true},
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 hidden = {false},
 citation_key = {HockettThesis},
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 private_publication = {false},
 abstract = {The work presented in this thesis was carried out with the ultimate aim of learning about the photoionization dynamics of polyatomic molecules. This is a complex problem; in order to obtain sufficient experimental data to shed light on the dynamics careful measurement of photoelectron angular distributions (PADs) is required. Ideally these measurements are rotationally-resolved, and the angular distributions measured correspond to the formation of the molecular ion in a single rotational state. The ionization event, in the dipole approximation, can be completely described by the dipole matrix elements. If sufficient experimental data to determine the radial components of the matrix elements and associated phases, the dynamical parameters, can be obtained the photoionization experiment may be said to be complete. Analysis of such experiments requires that the initial state of the molecular system is also known, to this end resonance-enhanced multi-photon ionization (REMPI) schemes can be used in order to populate a single quantum state prior to ionization. The experiments presented here follow this methodology, with various REMPI schemes used to prepare (pump) and ionize (probe) the molecule under study, and the velocity-map imaging (VMI) technique used to (simultaneously) record the photoelectron spectra and angular distributions. Two molecules have been studied experimentally, acetylene (C2H2) and ammonia (NH3). In both cases dynamical parameters pertaining to the formation of specific states (vibronic or vibrational) of the molecular ion have been determined from experimental data. Additionally, in the ammonia work, rotationally-resolved photoelectron images were obtained.},
 bibtype = {phdthesis},
 author = {Hockett, Paul}
}

The work presented in this thesis was carried out with the ultimate aim of learning about the photoionization dynamics of polyatomic molecules. This is a complex problem; in order to obtain sufficient experimental data to shed light on the dynamics careful measurement of photoelectron angular distributions (PADs) is required. Ideally these measurements are rotationally-resolved, and the angular distributions measured correspond to the formation of the molecular ion in a single rotational state. The ionization event, in the dipole approximation, can be completely described by the dipole matrix elements. If sufficient experimental data to determine the radial components of the matrix elements and associated phases, the dynamical parameters, can be obtained the photoionization experiment may be said to be complete. Analysis of such experiments requires that the initial state of the molecular system is also known, to this end resonance-enhanced multi-photon ionization (REMPI) schemes can be used in order to populate a single quantum state prior to ionization. The experiments presented here follow this methodology, with various REMPI schemes used to prepare (pump) and ionize (probe) the molecule under study, and the velocity-map imaging (VMI) technique used to (simultaneously) record the photoelectron spectra and angular distributions. Two molecules have been studied experimentally, acetylene (C2H2) and ammonia (NH3). In both cases dynamical parameters pertaining to the formation of specific states (vibronic or vibrational) of the molecular ion have been determined from experimental data. Additionally, in the ammonia work, rotationally-resolved photoelectron images were obtained.

@article{
 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 A1Au acetylene.},
 type = {article},
 year = {2007},
 pages = {154308},
 volume = {127},
 websites = {http://dx.doi.org/10.1063/1.2790443},
 month = {10},
 day = {21},
 id = {c4b10860-f59e-371d-8ae4-6607334eb380},
 created = {2012-07-20T19:15:08.000Z},
 accessed = {2012-07-20},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-03-14T07:19:21.662Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2007a},
 private_publication = {false},
 abstract = {We present a fit to photoelectron angular distributions (PADs) measured following the photoionization of rotationally selected A1Au state acetylene. In the case of the 4(1)2Sigmau- 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.},
 bibtype = {article},
 author = {Hockett, Paul and Reid, Katharine L},
 doi = {10.1063/1.2790443},
 journal = {The Journal of chemical physics},
 number = {15}
}

We present a fit to photoelectron angular distributions (PADs) measured following the photoionization of rotationally selected A1Au state acetylene. In the case of the 4(1)2Sigmau- 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.

@article{
 title = {Complete determination of the photoionization dynamics of a polyatomic molecule. I. Experimental photoelectron angular distributions from A1Au acetylene.},
 type = {article},
 year = {2007},
 pages = {154307},
 volume = {127},
 websites = {http://dx.doi.org/10.1063/1.2790442},
 month = {10},
 day = {21},
 id = {1143f07e-6b2a-3592-b27a-2b22d69d4e5d},
 created = {2012-07-20T19:17:01.000Z},
 accessed = {2012-07-20},
 file_attached = {true},
 profile_id = {929c804b-e5d8-3f59-bf8f-9e904e082c0f},
 last_modified = {2017-09-15T23:12:51.739Z},
 read = {true},
 starred = {false},
 authored = {true},
 confirmed = {true},
 hidden = {false},
 citation_key = {Hockett2007},
 private_publication = {false},
 abstract = {Angle-resolved photoelectron spectra from rotationally selected A1Au 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 A1Au state indicates the potential of a "complete" determination of the photoionization dynamics of the A1Au state. This is further investigated in the following paper.},
 bibtype = {article},
 author = {Hockett, Paul and King, Adrian K and Powis, Ivan and Reid, Katharine L},
 doi = {10.1063/1.2790442},
 journal = {The Journal of chemical physics},
 number = {15}
}

Angle-resolved photoelectron spectra from rotationally selected A1Au 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 A1Au state indicates the potential of a "complete" determination of the photoionization dynamics of the A1Au state. This is further investigated in the following paper.