A new non-Abelian topological superfluid of cold Fermi gases in anisotropic and spin-dependent optical lattices

To realize a non-Abelian s-wave topological superfluid of cold Fermi gases, generally a Zeeman energy splitting larger than the superfluid pairing gap is necessary. In this paper, we find that using an anisotropic and spin-dependent optical lattice to trap gases, a new non-Abelian topological superfluid phase appears, in contrast to an isotropic and spin-independent optical lattice. A characteristic of this new non-Abelian topological superfluid is that the Zeeman energy splitting can be smaller than the superfluid pairing gap. By self-consistently solving the gap equation and considering the competition against the normal state and phase separation, this new phase is also stable. We also investigate edge states and the effects of a harmonic trap potential. (Some figures may appear in colour only in the online journal)