Irreversible Work Reduction by Disorder in Many-Body Quantum Systems

TL;DR

This paper investigates how disorder in many-body quantum systems, specifically an Ising spin chain, can reduce irreversible work during a quench, revealing a disorder-induced lubrication effect influenced by the disorder's distribution.

Contribution

It demonstrates that strong disorder can decrease irreversible work in quantum spin chains, introducing a disorder-induced lubrication phenomenon dependent on the disorder distribution.

Findings

Weak disorder increases irreversible work.

Strong disorder can reduce irreversible work.

Disorder effects depend on the distribution type.

Abstract

We study the effect of disorder on work exchange associated to quantum Hamiltonian processes by considering an Ising spin chain in which the strength of coupling between spins are randomly drawn from either Normal or Gamma distributions. The chain is subjected to a quench of the external transverse field which induces this exchange of work. In particular, we study the irreversible work incurred by a quench as a function of the initial temperature, field strength and magnitude of the disorder. While presence of weak disorder generally increases the irreversible work generated, disorder of sufficient strength can instead reduce it, giving rise to a disorder induced lubrication effect. This reduction of irreversible work depends on the nature of the distribution considered, and can either arise from acquiring the behavior of an effectively smaller quench for the Normal-distributed spin couplings, or that of effectively single spin dynamics in the case of Gamma distributed couplings.