Calorimetric measurement of quantum work

TL;DR

This paper proposes using calorimetric measurements to experimentally test quantum fluctuation relations like the Jarzynski equality in a superconducting two-level system, enabling analysis of quantum work and dissipation.

Contribution

It introduces a calorimetric approach for testing quantum fluctuation relations in a feasible superconducting system, bridging theory and experiment.

Findings

Calorimetric measurement can test quantum fluctuation relations.

Feasible experimental setup with superconducting Cooper pair box.

Analysis of dissipation distribution in quantum systems.

Abstract

To define the work performed on a driven quantum system in a physically sound way has turned out to be a truly non-trivial task, except in some special cases of limited applicability. This topic has been in a focus of intense research recently in the attempts to generalize the classical fluctuation relations into the quantum regime. Here we propose and demonstrate that a calorimetric measurement gives both a theoretical and experimental tool to test the Jarzynski equality (JE) and other fluctuation relations in a quantum system, and to analyze the distribution of dissipation in them, based on the very principle of conservation of energy. We focus on an experimentally feasible two-level system, a superconducting Cooper pair box subject to Landau-Zener interband transitions. Because of the small heat capacity and weak relaxation to the phonon bath, the calorimetric measurement on the electron gas (resistor) turns out to be a very feasible experimental method.