Fulde-Ferrell superfluidity in ultracold Fermi gases with Rashba spin-orbit coupling

Abstract

We theoretically investigate the inhomogeneous Fulde-Ferrell (FF) superfluidity in a three-dimensional atomic Fermi gas with Rashba spin-orbit coupling near a broad Feshbach resonance. We show that within mean-field theory the FF superfluid state is always more favorable than the standard Bardeen-Cooper-Schrieffer superfluid state when an in-plane Zeeman field is applied. We present a qualitative finite-temperature phase diagram near resonance and argue that the predicted FF superfluid is observable with experimentally attainable temperatures (i.e. T ∼ 0.2TF, where TF is the characteristic Fermi degenerate temperature). © IOP Publishing and Deutsche Physikalische Gesellschaft.