Non-adiabatic dynamics of superfluid spin-orbit coupled degenerate Fermi gas

TL;DR

This paper investigates the non-adiabatic dynamics of superfluid spin-orbit coupled Fermi gases in two dimensions, revealing how spin-orbit coupling influences steady state behaviors under sudden changes in system parameters.

Contribution

It provides exact solutions for the evolution of pairing amplitude in non-adiabatic conditions, highlighting the impact of spin-orbit coupling on steady state regimes.

Findings

Spin-orbit coupling reduces the parameter space for oscillating pairing states.

Exact expressions for steady state pairing amplitude after population imbalance removal.

Identification of a regime where dynamics are governed by fewer equations, akin to integrable systems.

Abstract

We study a problem of non-adiabatic superfluid dynamics of spin-orbit coupled neutral fermions in two spatial dimensions. We focus on the two cases when the out-of-equilibrium conditions are initiated either by a sudden change of the pairing strength or the population imbalance. For the case of zero population imbalance and within the mean-field approximation, the non-adiabatic evolution of the pairing amplitude in a collisionless regime can be found exactly by employing the method of Lax vector construction. Our main finding is that the presence of the spin-orbit coupling significantly reduces the region in the parameter space where a steady state with periodically oscillating pairing amplitude is realized. For the collisionless dynamics initiated by a sudden disappearance of the population imbalance we obtain an exact expression for the steady state pairing amplitude. In the general case of quenches to a state with finite population imbalance we show that there is a region in the steady state phase diagram where at long times the pairing amplitude dynamics is governed by the reduced number of the equations of motion in full analogy with exactly integrable case.