Condensate fraction of a resonant Fermi gas with spin-orbit coupling in three and two dimensions

TL;DR

This paper investigates how laser-induced spin-orbit coupling influences the condensate fraction across the BCS-BEC crossover in a Fermi gas, revealing that spin-orbit interaction enhances singlet pairing on the BCS side and suppresses it on the BEC side.

Contribution

It provides a detailed calculation of the condensate fraction in 2D and 3D Fermi gases with spin-orbit coupling, highlighting its effectiveness as a crossover indicator and analyzing the effects on singlet and triplet pairings.

Findings

Spin-orbit coupling enhances singlet condensate fraction on the BCS side.

Spin-orbit coupling suppresses singlet condensate fraction on the BEC side.

Condensate fraction is a better crossover indicator than chemical potential or pairing gap.

Abstract

We study the effects of laser-induced Rashba-like spin-orbit coupling along the BCS-BEC crossover of a Feshbach resonance for a two-spin-component Fermi gas. We calculate the condensate fraction in three and two dimensions and find that this quantity characterizes the crossover better than other quantities, like the chemical potential or the pairing gap. By considering both the singlet and the triplet pairings, we calculate the condensate fraction and show that a large enough spin-orbit interaction enhances the singlet condensate fraction in the BCS side while suppressing it on the BEC side.