Instability of superfluid Fermi gases induced by a rotonlike density mode in optical lattices
Instability of superfluid Fermi gases induced by a rotonlike density mode in optical lattices
We study the stability of superfluid Fermi gases in deep optical lattices in the BCS--Bose-Einstein condensation (BEC) crossover at zero temperature. Within the tight-binding attractive Hubbard model, we calculate the spectrum of the low-energy Anderson-Bogoliubov (AB) mode as well as the single-particle excitations in the presence of superfluid flow in …