Verifying detailed fluctuation relations for discrete feedback-controlled quantum dynamics

TL;DR

This paper proposes a practical quantum interferometric method to experimentally verify detailed fluctuation relations in feedback-controlled quantum systems, enabling thermodynamic analysis far from equilibrium.

Contribution

It introduces a feasible experimental approach using quantum interferometry to verify fluctuation relations under feedback control, which was previously challenging.

Findings

Developed two detailed fluctuation relations for quantum feedback dynamics.

Proposed a quantum interferometric strategy for experimental verification.

Illustrated the method with an analytical example.

Abstract

Discrete quantum feedback control consists of a managed dynamics according to the information acquired by a previous measurement. Energy fluctuations along such dynamics satisfy generalized fluctuation relations, which are useful tools to study the thermodynamics of systems far away from equilibrium. Due to the practical challenge to assess energy fluctuations in the quantum scenario, the experimental verification of detailed fluctuation relations in the presence of feedback control remains elusive. We present a feasible method to experimentally verify detailed fluctuation relations for discrete feedback control quantum dynamics. Two detailed fluctuation relations are developed and employed. The method is based on a quantum interferometric strategy that allows the verification of fluctuation relations in the presence of feedback control. An analytical example to illustrate the applicability of the method is discussed. The comprehensive technique introduced here can be experimentally implemented at a microscale with the current technology in a variety of experimental platforms.