Trapped Fermi gases with Rashba spin-orbit coupling in two dimensions

Abstract

Here we consider both balanced and imbalanced Fermi gases throughout the BCS-BEC evolution, and we study the effects of spin-orbit coupling (SOC) on the spontaneously induced countercirculating mass currents and the associated intrinsic angular momentum via the Bogoliubov-de Gennes (BdG) formalism. In particular, we find that even a small SOC destabilizes Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) type spatially modulated superfluid phases and phase-separated states against the polarized superfluid phase. We also show that the continuum of the quasiparticle and quasihole excitation spectrum can be connected by zero, one, or two discrete branches of interface modes, depending on the number of interfaces between a topologically trivial phase and a nontrivial phase.