Sound velocity and dimensional crossover in a superfluid Fermi gas in an optical lattice
arXiv:cond-mat/0512010 · doi:10.1103/PhysRevA.73.033620
Abstract
We study the sound velocity in cubic and non-cubic three-dimensional optical lattices. We show how the van Hove singularity of the free Fermi gas is smoothened by interactions and eventually vanishes when interactions are strong enough. For non-cubic lattices, we show that the speed of sound (Bogoliubov-Anderson phonon) shows clear signatures of dimensional crossover both in the 1D and 2D limits.
16 pages, 9 figures, replaced with the published version