Dynamical fermionization in one-dimensional spinor gases at finite temperature

TL;DR

This paper analytically and numerically investigates dynamical fermionization in one-dimensional spinor gases at finite temperature, showing the momentum distribution approaches that of noninteracting fermions with a renormalized chemical potential after trap release.

Contribution

It provides the first analytical proof of dynamical fermionization at finite temperature for spinor gases with strong interactions, extending previous zero-temperature results.

Findings

Momentum distribution approaches that of spinless fermions at the same temperature.

Analytical proof valid for all spinor gases with strong repulsive interactions.

Numerical validation using nonequilibrium Lenard's formula for the Gaudin-Yang model.

Abstract

Following the removal of axial confinement, the momentum distribution of a Tonks-Girardeau gas approaches that of a system of noninteracting spinless fermions in the initial harmonic trap. This phenomenon, called dynamical fermionization, has been experimentally confirmed in the case of the Lieb-Liniger model and theoretically predicted in the case of multicomponent systems at zero temperature. We prove analytically that for all spinor gases with strong repulsive contact interactions at finite temperature the momentum distribution after release from the trap asymptotically approaches that of a system of spinless fermions at the same temperature but with a renormalized chemical potential which depends on the number of components of the spinor system. In the case of the Gaudin-Yang model we check numerically our analytical predictions using the results obtained from a nonequilibrium generalization of Lenard's formula describing the time evolution of the field-field correlators.