The generalized Gibbs ensemble as a pseudo-initial state: its predictive power revealed in a second quench

TL;DR

This paper investigates whether the generalized Gibbs ensemble can predict the response of an integrable quantum system to a second quench, demonstrating its predictive power in non-equilibrium dynamics through case studies.

Contribution

It extends the understanding of the generalized Gibbs ensemble by testing its predictive accuracy after a second quench in integrable systems.

Findings

GGE accurately predicts the system's response after a second quench.

Case studies with transverse Ising model and 1D hard-core bosons support the results.

Strengthens the relevance of GGE in non-equilibrium quantum dynamics.

Abstract

The generalized Gibbs ensemble has been shown to be relevant in the relaxation of a completely integrable system subject to a quantum quench, in the sense that it accurately predicts the steady values of some physical variables. We proceed to further question its relevance by giving the quenched system a second quench. The concern is whether the generalized Gibbs ensemble can also accurately predict the relaxed system's response to the second quench. Two case studies with the transverse Ising model and the hard-core bosons in one dimension yield an affirmative answer. The relevance of the generalized Gibbs ensemble in the non-equilibrium dynamics of integrable systems is then greatly strengthened.