Bath engineering enhanced quantum critical engines

TL;DR

This paper introduces a bath-engineered quantum engine (BEQE) that leverages critical scaling laws and the Kibble--Zurek mechanism to enhance performance near quantum phase transitions, outperforming traditional methods.

Contribution

It proposes a novel bath-engineering protocol for quantum engines that improves efficiency near critical points, especially in free fermionic systems, surpassing shortcuts to adiabaticity.

Findings

BEQE outperforms shortcuts to adiabaticity in free fermionic systems.

BEQE can surpass infinite-time engine performance under certain conditions.

The approach leverages critical scaling laws and the Kibble--Zurek mechanism.

Abstract

Driving a quantum system across quantum critical points leads to non-adiabatic excitations in the system. This in turn may adversely affect the functioning of a quantum machine which uses a quantum critical substance as its working medium. Here we propose a bath-engineered quantum engine (BEQE), in which we use the Kibble--Zurek mechanism and critical scaling laws to formulate a protocol for enhancing the performance of finite-time quantum engines operating close to quantum phase transitions. In the case of free fermionic systems, BEQE enables finite-time engines to outperform engines operating in the presence of shortcuts to adiabaticity, and even infinite-time engines under suitable conditions, thus showing the remarkable advantages offered by this technique. Open questions remain regarding the use of BEQE based on non-integrable models.