Phase separation in a polarized Fermi gas with spin-orbit coupling

Abstract

We study the phase separation of a spin polarized Fermi gas with spin-orbit coupling near a wide Feshbach resonance. As a result of the competition between spin-orbit coupling and population imbalance, the phase diagram for a uniform gas develops a rich structure of phase separation involving gapless superfluid states which are topologically non-trivial. We find that these novel gapless phases can be stabilized by intermediate spin-orbit coupling strengths. We then demonstrate the phase separation induced by an external trapping potential and discuss the optimal parameter region for the experimental observation of the gapless superfluid phases.