Spin dynamics in a spin-orbit coupled Fermi gas

TL;DR

This paper investigates the nonequilibrium spin dynamics of a trapped Fermi gas with spin-orbit coupling, revealing collapse and revival phenomena in magnetization and spin configurations, both analytically and numerically.

Contribution

It provides an analytical solution for non-interacting spin dynamics and explores the effects of interactions using numerical simulations.

Findings

Collapse and revival of magnetization in spin-polarized states

Oscillations between polarized state and spin helix in real space

Interactions modify but do not eliminate the observed dynamics

Abstract

We study the dynamics of a non-degenerate, harmonically trapped Fermi gas following a sudden ramp of the spin-orbit coupling strength. In the non-interacting limit, we solve the Boltzmann equation in the presence of spin orbit coupling analytically, and derive expressions for the dynamics of an arbitrary initial spin state. In particular we show that for a fully spin polarized initial state, the total magnetization exhibits collapse and revival dynamics in time with a period set by the trapping potential. In real space, this corresponds to oscillations between a fully polarized state and a spin helix. We numerically study the effect of interactions on the dynamics using a collisionless Boltzmann equation.