Nonequilibrium work and entropy production by quantum projective measurements

TL;DR

This paper explores how quantum projective measurements influence thermodynamics, demonstrating they perform work on the system, increase entropy, and satisfy the Jarzynski equality, linking quantum measurement to thermodynamic laws.

Contribution

It provides a theoretical framework connecting quantum measurements with thermodynamic principles, including the Jarzynski equality and entropy production.

Findings

Quantum measurements perform work on the system.

Work from measurements is dissipated as heat into the reservoir.

Measurements always increase the total entropy.

Abstract

We study the thermodynamics of quantum projective measurements by using the set up for the Jarzynski equality. We prove the fluctuations of energy change induced by measurements satisfy the Jarzynski equality, revealing that the quantum projective measurements perform a work on a measured system. When the system is brought into a thermal contact with a reservoir after measurements, the work done by projective measurements is totally dissipated in the form of heat from the system into the reservoir. Explicitly showing that the measurements always increase the total entropy, we prove the link between the second law of thermodynamics and the quantum measurement, and also provide a clue to the Landau-Lifshitz conjecture on the thermodynamic consequence of measurements.