Mpemba effects in open nonequilibrium quantum systems

TL;DR

This paper extends the classical Mpemba effect to open quantum systems, demonstrating that certain quantum systems can relax faster when initially hotter, with potential experimental verification through simple measurements.

Contribution

It introduces a generalized quantum Mpemba effect framework for open systems and shows how it can be detected via accessible observables like currents or energies.

Findings

Two types of quantum Mpemba effects are identified.

Quantum Mpemba effect can be detected with simple measurements.

The effect is demonstrated in a two-site Kitaev model with metallic leads.

Abstract

We generalize the classical thermal Mpemba effect (where an initially hot system relaxes faster to the final equilibrium state than a cold one) to open quantum systems coupled to several reservoirs. We show that, in general, two different types of quantum Mpemba effects are possible. They may be distinguished by quantum state tomography. However, the existence of a quantum Mpemba effect (without determining the type) can already be established by measuring simpler observables such as currents or energies. We illustrate our general results for the experimentally feasible case of an interacting two-site Kitaev model coupled to two metallic leads.