Spin-Depairing Transition of Attractive Fermi Gases on a Ring Driven by Synthetic Gauge Fields

TL;DR

This paper studies how synthetic gauge fields induce a spin-depairing transition in one-dimensional attractive Fermi gases, revealing a nonequilibrium transition from superfluid to normal states driven by quantum tunneling.

Contribution

It introduces a novel analysis of spin-depairing transitions in Fermi gases under synthetic gauge fields, combining Bethe ansatz and Landau-Dykhne methods, and explores effects of filling and continuum models.

Findings

Identification of a spin-depairing transition driven by gauge flux.

Analysis of transition probability dependence on filling.

Connection to dielectric breakdown in Mott insulators.

Abstract

Motivated by the recent experimental realization of synthetic gauge fields in ultracold atoms, we investigate one-dimensional attractive Fermi gases with a time-dependent gauge flux on the spin sector. By combining the methods of the Bethe ansatz with complex twists and Landau-Dykhne, it is shown that a spin-depairing transition occurs, which may represent a nonequilibrium transition from fermionic superfluids to normal states with spin currents caused by a many-body quantum tunneling. For the case of the Hubbard ring at half filling, our finding forms a dual concept with the dielectric breakdown of the Mott insulator discussed in Phys. Rev. B 81, 033103 (2010). We analyze cases of arbitrary filling and continuum model, and show how the filling affects the transition probability.