Fluctuation Relation for Qubit-Calorimetry

TL;DR

This paper introduces a model of a driven qubit interacting with a finite fermionic environment, deriving a fluctuation relation and exploring thermodynamic laws in quantum calorimetry.

Contribution

It presents a new stochastic model for qubit-calorimeter interactions and proves a fluctuation relation linking entropy production to quantum thermodynamics.

Findings

Proves a fluctuation relation for the qubit-calorimeter system

Defines a quantum notion of entropy production

Discusses thermodynamic laws in quantum measurement context

Abstract

Motivated by proposed thermometry measurement on an open quantum system, we present a simple model of an externally driven qubit interacting with a finite sized, fermion environment acting as calorimeter. The derived dynamics is governed by a stochastic Schr\"odinger equation coupled to the temperature change of the calorimeter. We prove a fluctuation relation and deduce from it a notion of entropy production. Finally, we discuss the first and second law associated to the dynamics.