Universal scaling of spin mixing dynamics in a strongly interacting one-dimensional Fermi gas

TL;DR

This paper investigates the long-time spin-mixing dynamics of a strongly interacting one-dimensional Fermi gas, revealing universal scaling laws and phenomena like superdiffusion, oscillations, and thermalization.

Contribution

It introduces a mapping to an inhomogeneous Heisenberg model and uncovers universal N^{1/4} scaling in spin dynamics of the system.

Findings

Superdiffusive spin transport observed

Universal N^{1/4} scaling of oscillations

Decrease of spin drag coefficient with particle number

Abstract

We study the spin-mixing dynamics of a one-dimensional strongly repulsive Fermi gas under harmonic confinement. By employing a mapping onto an inhomogeneous isotropic Heisenberg model and the symmetries under particle exchange, we follow the dynamics till very long times. Starting from an initial spin-separated state, we observe superdiffusion, spin-dipolar large amplitude oscillations and thermalization. We report a universal scaling of the oscillations with particle number N^1/4, implying a slow-down of the motion and the decrease of the zero-temperature spin drag coefficient as the particle number grows.