Time-dependent current-density-functional theory of spin-charge separation and spin drag in one-dimensional ultracold Fermi gases

TL;DR

This paper develops a microscopic, time-dependent current-density-functional theory to study non-equilibrium spin and charge dynamics, including spin-charge separation and spin drag, in one-dimensional ultracold Fermi gases after a quench.

Contribution

It introduces a novel theoretical framework capable of capturing non-linear and non-equilibrium effects in 1D Fermi gases, extending beyond linear response.

Findings

Demonstrates spin-charge separation in non-equilibrium dynamics

Shows spin-drag-induced broadening of spin packets

Validates the approach with numerical simulations

Abstract

Motivated by the large interest in the non-equilibrium dynamics of low-dimensional quantum many-body systems, we present a fully-microscopic theoretical and numerical study of the "charge" and "spin" dynamics in a one-dimensional ultracold Fermi gas following a quench. Our approach, which is based on time-dependent current-density-functional theory, is applicable well beyond the linear-response regime and produces both spin-charge separation and spin-drag-induced broadening of the spin packets.