Spin-orbit coupling induced enhancement of superconductivity in a two-dimensional repulsive gas of fermions

TL;DR

This paper investigates how Rashba spin-orbit coupling enhances superconductivity in a two-dimensional repulsive Fermi gas, leading to unconventional states that break time reversal symmetry, using a renormalization group approach.

Contribution

It introduces a detailed analysis of the impact of spin-orbit coupling on superconductivity in 2D fermionic systems, revealing enhancement effects and unconventional pairing states.

Findings

Superconductivity is enhanced with increasing spin-orbit coupling strength.

Unconventional superconducting states that break time reversal symmetry are identified.

The renormalization group approach effectively captures the instability leading to superconductivity.

Abstract

We study a model of a two-dimensional repulsive Fermi gas with Rashba spin-orbit coupling $\alpha_R$, and investigate the superconducting instability using renormalization group approach. We find that in general superconductivity is enhanced as the dimensionless ratio 1/2m\alpha_R^2/E_F$ increases, resulting in unconventional superconducting states which break time reversal symmetry.