Transition from Tonks-Girardeau gas to super-Tonks-Girardeau gas as an exact many-body dynamics problem

TL;DR

This paper studies the transition of a 1D Bose gas from a strongly repulsive to a strongly attractive regime, revealing the stability and properties of the super-Tonks-Girardeau phase through exact many-body dynamics.

Contribution

It provides an exact dynamical analysis of the super-Tonks-Girardeau gas, demonstrating its stability and calculating its breathing mode in agreement with experiments.

Findings

Super-Tonks-Girardeau gas is a stable excited state.

Breathing mode frequency matches experimental data.

The phase can be understood from the integrable Lieb-Liniger model.

Abstract

We investigate transition of a one-dimensional interacting Bose gas from a strongly repulsive regime to a strongly attractive regime, where a stable highly excited state known as the super Tonks-Girardeau gas was experimentally realized very recently. By solving exact dynamics of the integrable Lieb-Liniger Bose gas, we demonstrate that such an excited gas state can be a very stable dynamic state. Furthermore we calculate the breathing mode of the super Tonks-Girardeau gas which is found to be in good agreement with experimental observation. Our results show that the highly excited super Tonks-Girardeau gas phase can be well understood from the fundamental theory of the solvable Bose gas.