Nonequilibrium work and entropy production by quantum projective measurements

Juyeon Yi, Yong Woon Kim

Published 2012-11-19, updated 2015-08-28Version 2

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.