Analytic results for a quantum quench from free to hard-core one dimensional bosons

TL;DR

This paper provides exact analytical results for the dynamics of a one-dimensional Bose gas after a quantum quench from free to hard-core interactions, demonstrating the GGE's validity even with nonlinear mode relations.

Contribution

It offers the first exact analytical solution for the density-density correlation function post-quench in a nonlinear mode relation system, confirming GGE applicability.

Findings

Exact time evolution of density-density correlations derived

Stationary state described by GGE with restored Wick's theorem

Results applicable to experimentally relevant Bose gas quenches

Abstract

It is widely believed that the stationary properties after a quantum quench in integrable systems can be described by a generalized Gibbs ensemble (GGE), even if all the analytical evidence is based on free theories in which the pre- and post-quench modes are linearly related. In contrast, we consider the experimentally relevant quench of the one-dimensional Bose gas from zero to infinite interaction, in which the relation between modes is nonlinear, and consequently Wick's theorem does not hold. We provide exact analytical results for the time evolution of the dynamical density-density correlation function at any time after the quench and we prove that its stationary value is described by a GGE in which Wick's theorem is restored.