Role reversal in quantum Mpemba effect

TL;DR

This paper explores the quantum Mpemba effect in a dissipative Dicke model, identifying conditions for its occurrence and revealing a novel role reversal phenomenon where the relaxation order of states can invert based on system parameters.

Contribution

It introduces the concept of role reversal in the quantum Mpemba effect and provides criteria for its occurrence in a dissipative Dicke model using various relaxation measures.

Findings

Existence of role reversal in the quantum Mpemba effect.

Quantum coherence and entanglement as indicators of the effect.

Criteria for the occurrence of the quantum Mpemba effect.

Abstract

We investigate the quantum Mpemba effect in a dissipative Dicke model, which consists of a spin-1/2 ensemble coupled to a bosonic mode, which in turn is coupled to a bosonic bath. We derive a sufficient criterion for occurrence of the quantum Mpemba effect, characterized by quantum coherence, in this model. We introduce the phenomenon of role reversal in the Mpemba effect, wherein changes in the system parameters invert the relaxation ordering of a given pair of initial states that exhibit the Mpemba effect, causing the faster-relaxing state to become slower and vice versa. We find the existence of role reversal in Mpemba effect for this Dicke model using different relaxation measures, including differential quantum coherence and entanglement, and trace distance, between the time-evolved and steady states.