- Open Access
Broken detailed balance and entropy production in completely positive and trace-preserving quantum Brownian motion
Phys. Rev. Research 8, 033216 – Published 21 August, 2026
DOI: https://doi.org/10.1103/qqxn-qc4g
Abstract
We rigorously analyze the nonequilibrium thermodynamic behavior of various formulations of quantum Brownian motion using the framework of stochastic thermodynamics. While the widely used Caldeira-Leggett master equation exhibits desirable thermodynamic features—such as the fulfillment of a detailed balance—it fails to ensure complete positivity. In contrast, several completely positive and trace-preserving extensions turn out to be thermodynamically controversial. We show that such extensions introduce anomalous phase-space structures that violate detailed balance at the steady state, leading to nonvanishing entropy production and spurious nonequilibrium currents lacking a clear physical interpretation. Our results highlight a fundamental tension between quantum consistency and thermodynamic equilibration in open quantum systems.
Physics Subject Headings (PhySH)
- Brownian motion
- Diffusion
- Dissipative dynamics
- Irreversible processes
- Noise
- Nonequilibrium & irreversible thermodynamics
- Nonequilibrium statistical mechanics
- Open quantum systems
- Open quantum systems & decoherence
- Quantum correlations, foundations & formalism
- Quantum statistical mechanics
- Quantum thermodynamics
- Stochastic processes
- Stochastic thermodynamics
- Thermodynamics
- Brownian dynamics
- Dissipative particle dynamics
- Fokker–Planck equation
- Lindblad equation
- Phase space dynamics
Article Text
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