Thermodynamic deficiencies of some simple Lindblad operators

TL;DR

This paper critically examines certain simple Lindblad operators used in quantum dynamics, revealing thermodynamic inconsistencies and proposing an alternative stochastic method, especially highlighting limitations in local Lindblad approaches.

Contribution

It identifies thermodynamic deficiencies in common Lindblad operators and introduces an alternative stochastic framework for dissipative quantum systems.

Findings

Some Lindblad operators violate thermodynamic laws

Local Lindblad approaches can fail in complex models

An alternative stochastic method is proposed

Abstract

Master equations of Lindblad type have attained prominent status in the fields of quantum optics and quantum information since they are guaranteed to satisfy fundamental notions of quantum dynamics such as complete positivity. When Lindblad operators are used to describe thermal reservoirs in contact with an open quantum system, the fundamental laws of thermodynamics and the fluctuation-dissipation theorem provide additional mandatory criteria. We show several examples of innocent-looking Lindblad operators which have questionable properties in this regard. Compatibility criteria between Hamiltonian and Lindblad terms as well as consequences of their violation are discussed. An alternative stochastic approach to dissipative quantum dynamics is outlined and illustrated through a harmonic-chain model for which the approach of local Lindblad operators fails.