Time dependence of occupation numbers and thermalization time in closed chaotic many-body systems

TL;DR

This paper investigates how occupation numbers evolve over time in chaotic many-body quantum systems, demonstrating a simple theory that accurately predicts the onset of thermalization in such systems.

Contribution

It introduces a straightforward theoretical model for thermalization onset in chaotic many-body systems and validates it with numerical data.

Findings

Numerical data aligns with the simple theory for thermalization onset.

Chaotic compound states lead to predictable occupation number evolution.

Thermalization occurs rapidly in highly excited many-particle systems.

Abstract

We study the time evolution of occupation numbers for interacting Fermi-particles in the situation when exact compound states are "chaotic". This situation is generic for highly excited many-particles states in heavy nuclei, complex atoms, quantum dots, spin systems and quantum computer models. Numerical data show perfect agreement with a simple theory for the onset of thermalization in close systems of interacting particles.