Rashba spin-orbit coupling, strong interactions, and the BCS-BEC crossover in the ground state of the two-dimensional Fermi Gas

TL;DR

This paper provides precise numerical insights into how Rashba spin-orbit coupling influences pairing and many-body properties in a two-dimensional Fermi gas with strong interactions, aiding experimental and theoretical understanding.

Contribution

It offers the first ab initio quantum Monte Carlo calculations of a 2D Fermi gas with SOC, systematically exploring its ground state properties across parameters.

Findings

SOC induces complex pairing structures.

Equation of state and momentum distributions characterized.

Provides benchmarks for future experiments and theories.

Abstract

The recent experimental realization of spin-orbit coupled Fermi gases provides a unique opportunity to study the interplay between strong interaction and SOC in a tunable, disorder-free system. We present here precision ab initio numerical results on the two-dimensional, unpolarized, uniform Fermi gas with attractive interactions and Rashba SOC. Using auxiliary-field quantum Monte Carlo and incorporating recent algorithmic advances, we carry out exact calculations on sufficiently large system sizes to provide accurate results systematically as a function of experimental parameters. We obtain the equation of state, the momentum distributions, the pseudo-spin correlations and the pairing wave functions. Our results help illuminate the rich pairing structure induced by SOC, and provide benchmarks for theory and guidance to future experimental efforts.