Local quench spectroscopy of many-body quantum systems

TL;DR

This paper extends quench spectroscopy to local quenches, enabling the extraction of spectral properties and elementary excitation spectra of many-body quantum systems through out-of-equilibrium dynamics, with practical experimental implementations.

Contribution

It introduces a novel local quench spectroscopy method for analyzing many-body quantum systems, expanding beyond global quenches and providing a general scheme for various models.

Findings

Demonstrates how local quenches reveal spectral properties

Shows the method's applicability to ultracold gases and trapped ions

Provides numerical simulations validating the approach

Abstract

Quench spectroscopy is a relatively new method which enables the investigation of spectral properties of many-body quantum systems by monitoring the out-of-equilibrium dynamics of real-space observables after a quench. So far the approach has been devised for global quenches or using local engineering of momentum-resolved excitations. Here, we extend the quench spectroscopy method to local quenches. We show that it allows us to extract quantitative information about global properties of the system, and in particular the elementary excitation spectrum. Using state-of-the-art numerical methods, we simulate the out-of-equilibrium dynamics of a variety of quantum systems following various local quench protocols and demonstrate a general scheme for designing an appropriate local quench protocol for any chosen model. We provide detailed examples of how the local quench protocol can be realised in realistic current generation experiments, including ultracold atomic gases and trapped ion systems.