Topological superfluid in a trapped two-dimensional polarized Fermi gas with spin-orbit coupling

TL;DR

This paper investigates the conditions under which a topological superfluid phase can exist in a trapped two-dimensional polarized Fermi gas with spin-orbit coupling, identifying stable regions and experimental signatures.

Contribution

It systematically analyzes phase separation and optimal parameters for realizing topological superfluidity in such systems using a mean field approach.

Findings

Identifies parameter regions for stable topological superfluid phase.

Predicts unique signatures in momentum space density distribution.

Demonstrates experimental observability via time-of-flight imaging.

Abstract

We study the stability region of the topological superfluid phase in a trapped two-dimensional polarized Fermi gas with spin-orbit coupling and across a BCS-BEC crossover. Due to the competition between polarization, pairing interaction and spin-orbit coupling, the Fermi gas typically phase separates in the trap. Employing a mean field approach that guarantees the ground state solution, we systematically study the structure of the phase separation and investigate in detail the optimal parameter region for the preparation of the topologically non-trivial superfluid phase. We then calculate the momentum space density distribution of the topological superfluid state and demonstrate that the existence of the phase leaves a unique signature in the trap integrated momentum space density distribution which can survive the time-of-flight imaging process.