Quantum quenches in the sinh-Gordon model: steady state and one point correlation functions

TL;DR

This paper analyzes quantum quenches in the sinh-Gordon model, characterizing the long-time stationary state and computing expectation values of vertex operators using the quench action method, with insights into related models.

Contribution

It provides a complete description of the stationary state after quenches in the sinh-Gordon model and introduces a formula for expectation values based on thermodynamic Bethe ansatz.

Findings

Characterization of the stationary state via rapidity distribution

Exact expectation values for vertex operators

Insights into the sinh-Gordon and Lieb-Liniger model connection

Abstract

We consider quantum quenches to the sinh-Gordon integrable quantum field theory from a particular class of initial states. Our analysis includes the case of mass and interaction quenches starting from a non-interacting theory. By means of the recently developed quench action method, we fully characterize the stationary state reached at long times after the quench in terms of the corresponding rapidity distribution. We also provide exact results for the expectation values of arbitrary vertex operators in the post-quench stationary state by proposing a formula based on the analogy with the standard thermodynamic Bethe ansatz. Finally, we comment on the behavior of the post-quench stationary state under the mapping between the sinh-Gordon field theory and the one-dimensional Lieb-Liniger model.