Thermodynamic Properties of Rashba Spin-Orbit-Coupled Fermi Gas

TL;DR

This paper studies the thermodynamic behavior of a Rashba spin-orbit-coupled Fermi gas, revealing how Zeeman fields influence superfluid transition and phase structure using a beyond-mean-field T-matrix approach.

Contribution

It introduces a comprehensive analysis of thermodynamic properties of spin-orbit-coupled Fermi gases with Zeeman fields, including the effects on superfluid transition and exotic phases.

Findings

Out-of-plane and in-plane Zeeman fields have distinct effects on the Fermi gas.

In-plane Zeeman field induces Fulde-Ferrell superfluid below critical temperature.

Finite-momentum pseudo-gap phase appears above the critical temperature.

Abstract

We investigate the thermodynamic properties of a superfluid Fermi gas subject to Rashba spin-orbit coupling and effective Zeeman field. We adopt a T-matrix scheme that takes beyond-mean-field effects, which are important for strongly interacting systems, into account. We focus on the calculation of two important quantities: the superfluid transition temperature and the isothermal compressibility. Our calculation shows very distinct influences of the out-of-plane and the in-plane Zeeman fields on the Fermi gas. We also confirm that the in-plane Zeeman field induces a Fulde-Ferrell superfluid below the critical temperature and an exotic finite-momentum pseudo-gap phase above the critical temperature.