Dynamic density-density correlations in interacting Bose gases on optical lattices. Ejima, S., Fehske, H., & Gebhard, F. Journal of Physics: Conference Series, 391(1):012143, December, 2012.
Dynamic density-density correlations in interacting Bose gases on optical lattices [link]Paper  doi  abstract   bibtex   
In order to identify possible experimental signatures of the superfluid to Mott-insulator quantum phase transition we calculate the charge structure factor S(k, ω) for the one-dimensional Bose-Hubbard model using the dynamical density-matrix renormalisation group (DDMRG) technique. Particularly we analyse the behaviour of S(k, ω) by varying – at zero temperature–the Coulomb interaction strength within the first Mott lobe. For strong interactions, in the Mott-insulator phase, we demonstrate that the DDMRG results are well reproduced by a strong-coupling expansion, just as the quasi-particle dispersion. In the super-fluid phase we determine the linear excitation spectrum near k = 0. In one dimension, the amplitude mode is absent which mean-field theory suggests for higher dimensions.
@article{ejima_dynamic_2012,
	title = {Dynamic density-density correlations in interacting {Bose} gases on optical lattices},
	volume = {391},
	issn = {1742-6596},
	url = {http://iopscience.iop.org/1742-6596/391/1/012143},
	doi = {10.1088/1742-6596/391/1/012143},
	abstract = {In order to identify possible experimental signatures of the superfluid to Mott-insulator quantum phase transition we calculate the charge structure factor S(k, ω) for the one-dimensional Bose-Hubbard model using the dynamical density-matrix renormalisation group (DDMRG) technique. Particularly we analyse the behaviour of S(k, ω) by varying – at zero temperature–the Coulomb interaction strength within the first Mott lobe. For strong interactions, in the Mott-insulator phase, we demonstrate that the DDMRG results are well reproduced by a strong-coupling expansion, just as the quasi-particle dispersion. In the super-fluid phase we determine the linear excitation spectrum near k = 0. In one dimension, the amplitude mode is absent which mean-field theory suggests for higher dimensions.},
	language = {en},
	number = {1},
	urldate = {2015-02-06},
	journal = {Journal of Physics: Conference Series},
	author = {Ejima, S. and Fehske, H. and Gebhard, F.},
	month = dec,
	year = {2012},
	pages = {012143},
	file = {Ejima et al_2012_Dynamic density-density correlations in interacting Bose gases on optical.pdf:/home/schlady/.zotero/zotero/za3jlr8i.default/zotero/storage/HTX5EE7W/Ejima et al_2012_Dynamic density-density correlations in interacting Bose gases on optical.pdf:application/pdf;Snapshot:/home/schlady/.zotero/zotero/za3jlr8i.default/zotero/storage/FZGKI2IP/012143.html:text/html}
}
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