Almost complete revivals in quantum many-body systems

TL;DR

This paper demonstrates how to engineer quantum states in many-body systems that exhibit nearly complete revivals of local polarization, offering potential applications in benchmarking quantum simulators and secure information protocols.

Contribution

It introduces a method to construct initial states in nonintegrable spin systems that produce almost complete local polarization revivals at chosen times, advancing control in quantum dynamics.

Findings

Constructed states show near-perfect polarization revivals

Revivals can be used to benchmark quantum simulators

Proposed application for delayed secret disclosure

Abstract

Revivals of initial non-equilibrium states is an ever-present concern for the theory of dynamic thermalization in many-body quantum systems. Here we consider a nonintegrable lattice of interacting spins 1/2 and show how to construct a quantum state such that a given spin 1/2 is maximally polarized initially and then exhibits an almost complete recovery of the initial polarization at a predetermined moment of time. An experimental observation of such revivals may be utilized to benchmark quantum simulators with a measurement of only one local observable. We further propose to utilize these revivals for a delayed disclosure of a secret.