Repulsive dynamics of strongly attractive one-dimensional quantum gases

TL;DR

This paper investigates the nonequilibrium dynamics of strongly attractive one-dimensional quantum gases, revealing conditions under which attractive interactions mimic repulsive behavior and exploring implications for quantum droplets.

Contribution

It extends super-Tonks-Girardeau gas theory to nonequilibrium dynamics and introduces a novel mechanism for effective repulsion in strongly attractive systems.

Findings

Attractive forces can act as repulsive during certain dynamics

Identification of conditions for domain stability in Fermi gases

Implications for metastable quantum droplets

Abstract

We analyze the dynamics of one-dimensional quantum gases with strongly attractive contact interactions. We specify a class of initial states for which attractive forces effectively act as strongly repulsive ones during the time evolution. Our findings extend the theoretical results on the super-Tonks-Girardeau gas to a highly nonequilibrium dynamics. The novel mechanism is illustrated on the prototypical problem of the domain stability in a two-component Fermi gas. We also discuss nonlocal interactions and analyze universality of the presented results. Moreover, we use our conclusions to argue for the existence of metastable quantum droplets in the regime of strongly attractive contact and attractive dipolar interactions.