The quantum Mpemba effects

TL;DR

This paper reviews the quantum Mpemba effect, an anomalous phenomenon where hotter quantum systems can cool faster than cooler ones, discussing theoretical frameworks, experimental observations, and underlying mechanisms.

Contribution

It provides a comprehensive overview of the quantum Mpemba effect, highlighting recent progress, key mechanisms, and open questions in the field.

Findings

Quantum fluctuations influence relaxation dynamics.

Experimental evidence of the quantum Mpemba effect.

Role of symmetry and integrability in anomalous relaxation.

Abstract

The Mpemba effect, where a hotter system can equilibrate faster than a cooler one, has long been a subject of fascination in classical physics. In the past few years, significant theoretical and experimental progress has been made in understanding its occurrence in both classical and quantum systems. In this review, we provide a concise overview of the Mpemba effect in quantum systems, with a focus on both open and isolated dynamics which give rise to distinct manifestations of this anomalous non-equilibrium phenomenon. We discuss key theoretical frameworks, highlight experimental observations, and explore the fundamental mechanisms that give rise to anomalous relaxation behaviors. Particular attention is given to the role of quantum fluctuations, integrability, and symmetry in shaping equilibration pathways. Finally, we outline open questions and future directions.