Current-induced instability of superfluid Fermi gases in optical lattices
Current-induced instability of superfluid Fermi gases in optical lattices
We study the stability of superfluid flow of two-component Fermi gases in one-dimensional optical lattices. We find that the density fluctuation mode, the so-called Anderson-Bogoliubov mode, has the roton-like structure as seen in superfluid 4He. With increasing supercurrent, one of the roton-like minima reaches zero before the pair breaking occurs. …