Superfluid transition temperature of spin-orbit and Rabi coupled fermions with tunable interactions

TL;DR

This paper investigates how spin-orbit and Rabi couplings influence the superfluid transition temperature in fermionic systems across BCS-BEC regimes, revealing enhancements and phase transition nature changes.

Contribution

It provides a detailed analysis of the superfluid transition temperature considering spin-orbit and Rabi couplings, including derivation of the Ginzburg-Landau equation up to sixth order.

Findings

Spin-orbit coupling increases the critical temperature in the BEC regime.

Rabi coupling can change the phase transition from first to second order.

Derived a sixth-order Ginzburg-Landau equation for the system.

Abstract

We obtain the superfluid transition temperature of equal Rashba-Dresselhaus spin-orbit and Rabi coupled Fermi superfluids, from the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) regimes in three dimensions. Spin-orbit coupling enhances the critical temperature in the BEC limit, and can convert a first order phase transition in the presence of Rabi coupling into second order, as a function of the Rabi coupling for fixed interactions. We derive the Ginzburg-Landau equation to sixth power in the superfluid order parameter to describe both first and second order transitions as a function of spin-orbit and Rabi couplings.