Quantum Consensus Dynamics by Entangling Maxwell Demon

TL;DR

This paper presents a Maxwell demon that creates robust many-body entanglement to achieve quantum advantage, using a feedback protocol inspired by opinion consensus models, and establishes thermodynamic bounds related to entropy and work.

Contribution

It introduces a novel Maxwell demon protocol for generating entanglement and derives fundamental thermodynamic bounds for its operation, extending the second law to quantum many-body systems.

Findings

Maxwell demon can generate entanglement robust against noise.

Derived bounds relate entropy reduction and work extraction to information and irreversibility.

Reformulates the second law of thermodynamics for entangling Maxwell demons.

Abstract

We introduce a Maxwell demon which generates many-body entanglement robustly against bit-flip noises, which allows us to obtain quantum advantage. Adopting the protocol of the voter model used for opinion dynamics approaching consensus, the demon randomly selects a qubit pair and performs a quantum feedback control, in continuous repetitions. We derive upper bounds of the entropy reduction and the work extraction rates by demon's operation, which are determined by a competition between the quantum-classical mutual information acquired by the demon and the absolute irreversibility of the feedback control. Our finding of the upper bounds corresponds to a reformulation of the second law of thermodynamics under a class of Maxwell demon which generates many-body entanglement in a working substance.