Quantum work for sudden quenches in Gaussian random Hamiltonians

TL;DR

This paper derives an analytic expression for the work characteristic function in quantum sudden quenches using random matrix theory, applicable to Gaussian ensembles and valid across temperature ranges.

Contribution

It provides a novel analytic formula for the work characteristic function in quantum quenches with Gaussian random Hamiltonians, enhancing understanding of quantum thermodynamics.

Findings

Accurate description of work characteristic function for Gaussian ensembles.

Valid across all temperature ranges for single Hamiltonian realizations.

Bridges random matrix theory with quantum thermodynamics.

Abstract

In the context of nonequilibrium quantum thermodynamics, variables like work behave stochastically. A particular definition of the work probability density function (pdf) for coherent quantum processes allows the verification of the quantum version of the celebrated fluctuation theorems, due to Jarzynski and Crooks, that apply when the system is driven away from an initial equilibrium thermal state. Such a particular pdf depends basically on the details of the initial and final Hamiltonians, on the temperature of the initial thermal state and on how some external parameter is changed during the coherent process. Using random matrix theory we derive a simple analytic expression that describes the general behavior of the work characteristic function $G(u)$, associated with this particular work pdf for sudden quenches, valid for all the traditional Gaussian ensembles of Hamiltonians matrices. This formula well describes the general behavior of $G(u)$ calculated from single draws of the initial and final Hamiltonians in all ranges of temperatures.