Informational Mpemba Effect for Fast State Purification in Non-Hermitian System

TL;DR

This paper demonstrates a rapid state purification method in driven non-Hermitian quantum systems, revealing an informational Mpemba effect where more mixed states reach purity faster, enhancing quantum engineering capabilities.

Contribution

It introduces a novel purification technique leveraging collective reservoir engineering and uncovers an informational Mpemba effect in non-Hermitian quantum dynamics.

Findings

Efficient purification is governed by degeneracy of collective subradiant modes.

The system exhibits an informational Mpemba effect where more mixed states purify faster.

Driven non-Hermitian systems with engineered dissipation enhance quantum state purification.

Abstract

Quantum systems are inherently fragile to environmental fluctuations or decoherence, limiting their advantages in applications of quantum information and quantum computation. State purification offers a route to recover the purity of system under noisy conditions. Here, we demonstrate a rapid purification of initially mixed states by harnessing collective reservoir engineering in driven non-Hermitian qubit systems, together with multipartite entanglement generation in larger systems. We show that the onset of efficient purification-assisted entanglement generation is dictated by the degeneracy of collective subradiant modes, rather than by exceptional points. Moreover, the system dynamics manifests an informational Mpemba effect, i.e., a more mixed initial state reaches its steady state with unit purity at a faster rate, resembling the conventional Mpemba effect where a hotter system cools more rapidly. These results reveal a unique advantage of driven non-Hermitian quantum systems with engineered collective dissipation, enabling enhanced purification efficiency and offering new opportunities for quantum engineering.