Generalised linear response theory for the full quantum work statistics

TL;DR

This paper develops a linear response framework to describe the full quantum work statistics, revealing quantum-specific features and providing new tools for analyzing non-equilibrium quantum thermodynamics.

Contribution

It introduces a method to encode the entire work distribution in a single relaxation function, applicable to fast, perturbative quantum protocols without slow-driving assumptions.

Findings

Work distribution can be derived from a single relaxation function.

Quantum zero-point fluctuations increase work distribution dispersion.

New thermodynamic constraints for quantum work statistics in fast protocols.

Abstract

We consider a quantum system driven out of equilibrium via a small Hamiltonian perturbation. Building on the paradigmatic framework of linear response theory (LRT), we derive an expression for the full generating function of the dissipated work. Remarkably, we find that all information about the distribution can be encoded in a single quantity, the standard relaxation function in LRT, thus opening up new ways to use phenomenological models to study non-equilibrium fluctuations in complex quantum systems. Our results establish a number of refined quantum thermodynamic constraints on the work statistics that apply to regimes of perturbative but arbitrarily fast protocols, and do not rely on assumptions such as slow driving or weak coupling. Finally, our approach uncovers a distinctly quantum signature in the work statistics that originates from underlying zero-point energy fluctuations. This causes an increased dispersion of the probability distribution at short driving times, a feature that can be probed in efforts to witness non-classical effects in quantum thermodynamics.