Comparing classical and quantum equilibration

TL;DR

This paper demonstrates that quantum systems tend to equilibrate more readily than classical systems under measurement-based definitions, highlighting fundamental differences in their equilibration behaviors.

Contribution

It introduces a theory-independent framework for measurement-based equilibration, showing quantum systems equilibrate more easily than classical ones, especially with incomplete initial state knowledge.

Findings

Quantum equilibration is easier than classical under the proposed framework.

Quantum systems require weaker conditions to equilibrate when the initial state is mixed.

Equilibration is a fundamental aspect of quantum systems, less dependent on ignorance than classical systems.

Abstract

By using a physically-relevant and theory independent definition of measurement-based equilibration, we show quantitatively that equilibration is easier for quantum systems than for classical systems, in the situation where the initial state of the system is completely known (pure state). This shows that quantum equilibration is a fundamental, nigh unavoidable, aspect of physical systems, while classical equilibration relies on experimental ignorance. When the state is not completely known, a mixed state, this framework also shows quantum equilibration requires weaker conditions.