Kinetics and thermodynamics of a driven open quantum system

TL;DR

This paper compares Redfield and Landau-Zener theories in describing driven open quantum systems, demonstrating their potential equivalence and thermodynamic consistency under certain conditions.

Contribution

It analyzes the validity of Redfield and Landau-Zener theories using a simple model, showing they can produce identical quantum master equations and consistent thermodynamics.

Findings

Redfield and Landau-Zener theories can yield identical quantum master equations.

Both theories can describe nonequilibrium thermodynamics consistently.

Properly accounting for system-reservoir interaction energy is crucial.

Abstract

Redfield theory provides a closed kinetic description of a quantum system in weak contact with a very dense reservoir. Landau-Zener theory does the same for a time-dependent driven system in contact with a sparse reservoir. Using a simple model, we analyze the validity of these two theories by comparing their predictions with exact numerical results. We show that despite their a priori different range of validity, these two descriptions can give rise to an identical quantum master equation. Both theories can be used for a nonequilibrium thermodynamic description which we show is consistent with exact thermodynamic identities evaluated in the full system-reservoir space. We emphasize the importance of properly accounting for the system-reservoir interaction energy and of operating in regimes where the reservoir can be considered as close to ideal.