Quantum Fluctuation Relations for Ensembles of Wave Functions

Abstract

New quantum fluctuation relations are presented. In contrast with the the standard approach, where the initial state of the driven system is described by the (micro)canonical density matrix, here we assume that it is described by a (micro)canonical distribution of wave functions, as originally proposed by Schr\"odinger. While the standard fluctuation relations are based on von Neumann measurement postulate, these new fluctuation relations do not involve any quantum collapse, but involve instead a notion of work as the change in expectation of the Hamiltonian.