Reversal of relaxation due to dephasing environment

TL;DR

This paper demonstrates that by coupling a finite quantum system to a dephasing environment, it is possible to effectively reverse relaxation and restore initial observable values, with potential for precise control.

Contribution

It introduces a method to cancel relaxation in finite quantum systems through tailored dephasing environment coupling, supported by numerical simulations.

Findings

Relaxation can be effectively canceled in finite quantum systems.

Adjusting the coupling allows tuning the difference between initial and long-term observable values.

Numerical studies confirm the reversal of relaxation in a 1D interacting fermion system.

Abstract

We show that any finite quantum system $S$ can be coupled to a dephasing environment in such a way that the internal mechanism responsible for relaxation of observables acting on $S$ can be effectively canceled. By adjusting this coupling, the difference between the initial and the long--time expectation values of any observable on $S$ can be tuned to arbitrarily small however nonzero value. This statement is exemplified and visualized by numerical studies of relaxation in a generic one-dimensional system of interacting fermions.