Sound velocity and dimensional crossover in a superfluid Fermi gas in an optical lattice

T. Koponen; J. -P. Martikainen; J. Kinnunen; P. Torma

doi:10.1103/physreva.73.033620

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Sound velocity and dimensional crossover in a superfluid Fermi gas in an optical lattice

T. Koponen·J. -P. Martikainen·J. Kinnunen·P. Torma

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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.

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T. Koponen, J. -P. Martikainen, J. Kinnunen, P. Torma. 2006-03-27. Sound velocity and dimensional crossover in a superfluid Fermi gas in an optical lattice. https://doi.org/10.1103/physreva.73.033620

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