Spin-orbit coupling induced Fulde-Ferrell-Larkin-Ovchinnikov-like Cooper pairing and skyrmion-like polarization textures in trapped optical lattices

TL;DR

This paper explores how Zeeman fields and spin-orbit coupling induce exotic superfluid phases and polarization textures in trapped optical lattice Fermi gases, revealing new topological phenomena.

Contribution

It demonstrates the emergence of Fulde-Ferrell-like superfluidity and skyrmion-like polarization textures due to Zeeman and SOC interplay in optical lattices, analyzed via Bogoliubov-de Gennes theory.

Findings

Zeeman field and SOC induce Fulde-Ferrell superfluidity.

Skyrmion-like polarization textures appear near edges.

Interaction and anisotropy affect superfluid and textures.

Abstract

We study the interplay between the Zeeman field and spin-orbit coupling (SOC) in harmonically trapped Fermi gases loaded into a two-dimensional single-band tight-binding optical lattice. Using the Bogoliubov-de Gennes theory, we find that the Zeeman field combined with a Rashba SOC gives rise to $(i)$ Fulde-Ferrell-like superfluidity and $(ii)$ skyrmion-like polarization textures near the edges of the system. We also discussed the effects of interaction, temperature, SOC anisotropy and Zeeman field anisotropy on the superfluid ground state and polarization textures.