Bound on the rate of entropy change in open quantum systems

TL;DR

This paper establishes a general bound on how quickly the von Neumann entropy can change in open quantum systems, showing that the average rate is typically small under broad conditions.

Contribution

It provides a universal bound on the entropy change rate in open quantum systems, applicable to a wide range of initial states and interactions.

Findings

Time-average entropy change rate is bounded by a system-dependent function.

The bound holds for almost all initial states of system and bath.

The result is valid under general conditions for arbitrary quantum systems.

Abstract

We study the temporal rate of variations of the von Neumann entropy in an open quantum system which interacts with a bath. We show that for almost all initial states of the bath and the system, the time-average of the rate of entropy change is bounded by a function which depends on various properties of the system and environment, and is mostly relatively small. This result holds true under fairly general conditions in almost any arbitrary quantum system.