Effects of interaction and polarization on spin-charge separation: A time-dependent spin-density-functional theory study

TL;DR

This study uses time-dependent spin-density-functional theory to explore how interaction strength and polarization influence spin-charge separation in a one-dimensional fermionic system after a local quench.

Contribution

It demonstrates the effects of interaction quench and polarization on spin-charge separation, providing insights into nonequilibrium dynamics in one-dimensional quantum systems.

Findings

Charge velocity exceeds spin velocity in repulsive interactions.

Interaction quench suppresses spin-charge separation.

Polarization reduces the degree of spin-charge separation.

Abstract

We calculate the nonequilibrium dynamic evolution of a one-dimensional system of two-component fermionic atoms after a strong local quench by using a time-dependent spin-density-functional theory. The interaction quench is also considered to see its influence on the spin-charge separation. It is shown that the charge velocity is larger than the spin velocity for the system of on-site repulsive interaction (Luttinger liquid), and vise versa for the system of on-site attractive interaction (Luther-Emery liquid). We find that both the interaction quench and polarization suppress the spin-charge separation.