The Two-Dimensional Bose-Einstein Condensate
摘要
We study the Hartree-Fock-Bogoliubov mean-field theory as applied to a two-dimensional finite trapped Bose gas at low temperatures and find that, in the Hartree-Fock approximation, the system can be described either with or without the presence of a condensate; this is true in the thermodynamic limit as well. Of the two solutions, the one that includes a condensate has a lower free energy at all temperatures. However, the Hartree-Fock scheme neglects the presence of phonons within the system, and when we allow for the possibility of phonons we are unable to find condensed solutions; the uncondensed solutions, on the other hand, are valid also in the latter, more general scheme. Our results confirm that low-energy phonons destabilize the two-dimensional condensate.
引用
@article{arxiv.cond-mat/0203175,
title = {The Two-Dimensional Bose-Einstein Condensate},
author = {Juan Pablo Fernandez and William J. Mullin},
journal= {arXiv preprint arXiv:cond-mat/0203175},
year = {2007}
}
备注
8 pages, 3 figures, REVTeX 4. To appear in J. Low Temp. Phys. Corrected a mistake in a calculation and changed the conclusions accordingly