A quantum version of free energy - irreversible work relations

TL;DR

This paper develops a quantum analogue of the Jarzynski relation, linking work distributions and free energy differences in quantum systems, by defining quantum work and ensembles, unifying various regimes under a general heat and time-reversal framework.

Contribution

It introduces a quantum version of the Jarzynski relation with a new definition of quantum work and ensembles, unifying different regimes in a comprehensive framework.

Findings

Quantum Jarzynski relation derived

Unified treatment of classical and quantum regimes

Highlights the role of heat and time-reversal symmetry

Abstract

We give a quantum version of the Jarzynski relation between the distribution of work done over a certain time-interval on a system and the difference of equilibrium free energies. The main new ingredient is the identification of work depending on the quantum history of the system and the proper definition of various quantum ensembles over which the averages should be made. We also discuss a number of different regimes that have been considered by other authors and which are unified in the present set-up. In all cases, and quantum or classical, it is a general relation between heat and time-reversal that makes the Jarzynski relation so universally valid.