Foundation of Statistical Mechanics under experimentally realistic conditions

TL;DR

This paper shows that isolated macroscopic quantum systems naturally equilibrate under realistic experimental conditions, validating the core principles of Statistical Mechanics for such systems.

Contribution

It demonstrates equilibration of quantum systems with realistic initial states and measurement limitations, supporting the foundational assumptions of Statistical Mechanics.

Findings

Quantum systems equilibrate under realistic conditions

Predictions of Statistical Mechanics are recovered at equilibrium

Equilibration occurs with non-equilibrium initial states

Abstract

We demonstrate the equilibration of isolated macroscopic quantum systems, prepared in non-equilibrium mixed states with significant population of many energy levels, and observed by instruments with a reasonably bound working range compared to the resolution limit. Both properties are fulfilled under many, if not all, experimentally realistic conditions. At equilibrium, the predictions and limitations of Statistical Mechanics are recovered.