Entropy Production in Continuously Measured Gaussian Quantum Systems

TL;DR

This paper develops a phase space-based framework to quantify entropy production in continuously measured Gaussian quantum systems, extending thermodynamic irreversibility concepts into quantum regimes.

Contribution

It introduces a novel approach to assess entropy production in quantum systems under continuous measurement, incorporating measurement back-action and information gain.

Findings

Formulation of a sharpened second law of thermodynamics for quantum systems

Application of the framework to relevant physical examples

Quantitative analysis of entropy production rate in monitored Gaussian systems

Abstract

The entropy production rate is a key quantity in non-equilibrium thermodynamics of both classical and quantum processes. No universal theory of entropy production is available to date, which hinders progress towards its full grasping. By using a phase space-based approach, here we take the current framework for the assessment of thermodynamic irreversibility all the way to quantum regimes by characterizing entropy production -- and its rate -- resulting from the continuous monitoring of a Gaussian system. This allows us to formulate a sharpened second law of thermodynamics that accounts for the measurement back-action and information gain from a continuously monitored system. We illustrate our framework in a series of physically relevant examples.