Coherent feedback-enhanced asymmetry of thermal process in open quantum systems: cavity optomechanics

Abstract

 Entropy production is a fundamental quantity in nonequilibrium thermodynamics, serving as a direct measure of the irreversibility associated with physical processes. In this work, we investigate the steady-state enhancement of irreversibility by employing a coherent feedback loop. We evaluate the steady-state entropy production rate and quantum correlations by applying the quantum phase-space formulation to calculate the entropy change. Our study reveals the essential contribution of coherent feedback to the thermal bath’s input noise operators, resulting in the system being driven far from thermal equilibrium. Our analysis shows that, in the small-coupling limit, the entropy production rate is proportional to the quantum mutual information. As an application, we use a Fabry–Pérot cavity optomechanical system and show that the peaks of the entropy production corresponding to the heating/cooling of the movable mirror are enhanced. Therefore, we conclude that irreversibility and quantum correlations are not independent and must be analyzed jointly. The results demonstrate the possibility of enhancing entropy production and pave the way for promising quantum thermal applications through a coherent feedback loop.