Time-reversal symmetry and fluctuation relations in non-equilibrium quantum steady states

TL;DR

This paper derives fluctuation relations for non-equilibrium quantum steady states using time-reversal symmetry, linking large deviation functions to mean currents and illustrating with models like the resonant level and conformal models.

Contribution

It provides a simple derivation of fluctuation relations from time-reversal symmetry and explores conditions for extended relations in quantum systems.

Findings

Fluctuation relations are derived from time-reversal symmetry.

Pure transmission implies extended fluctuation relations.

Examples include the resonant level model and conformal models.

Abstract

In this note, we present a simple derivation, from time-reversal symmetry, of fluctuation relations for steady-state large deviation functions in non-equilibrium quantum systems. We further show that a condition of pure transmission implies extended fluctuation relations, connecting large deviation functions to mean currents at shifted temperatures and chemical potentials. We illustrate these concepts in various examples, including the interacting resonant level model and conformal or integrable models.