Saved in:
Bibliographic Details
Main Authors: Lenk, Marvin, Biswas, Sayak, Posazhennikova, Anna, Kroha, Johann
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2505.20593
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915354454786048
author Lenk, Marvin
Biswas, Sayak
Posazhennikova, Anna
Kroha, Johann
author_facet Lenk, Marvin
Biswas, Sayak
Posazhennikova, Anna
Kroha, Johann
contents One of the fundamental problems of quantum statistical physics is how an ideally isolated quantum system can ever reach thermal equilibrium behavior despite the unitary time evolution of quantum-mechanical systems. Here, we study, via explicit time evolution for the generic model system of an interacting, trapped Bose gas with discrete single-particle levels, how the measurement of one or more observables subdivides the system into observed and non-observed Hilbert subspaces and the tracing over the non-measured quantum numbers defines an effective, thermodynamic bath, induces the entanglement of the observed Hilbert subspace with the bath, and leads to a bi-exponential approach of the entanglement entropy and of the measured observables to thermal equilibrium behavior as a function of time. We find this to be more generally fulfilled than in the scenario of the eigenstate thermalization hypothesis (ETH), namely for both local particle occupation numbers and non-local density correlation functions, and independent of the specific initial quantum state of the time evolution.
format Preprint
id arxiv_https___arxiv_org_abs_2505_20593
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Measurement-Induced Dynamical Quantum Thermalization
Lenk, Marvin
Biswas, Sayak
Posazhennikova, Anna
Kroha, Johann
Quantum Physics
Quantum Gases
One of the fundamental problems of quantum statistical physics is how an ideally isolated quantum system can ever reach thermal equilibrium behavior despite the unitary time evolution of quantum-mechanical systems. Here, we study, via explicit time evolution for the generic model system of an interacting, trapped Bose gas with discrete single-particle levels, how the measurement of one or more observables subdivides the system into observed and non-observed Hilbert subspaces and the tracing over the non-measured quantum numbers defines an effective, thermodynamic bath, induces the entanglement of the observed Hilbert subspace with the bath, and leads to a bi-exponential approach of the entanglement entropy and of the measured observables to thermal equilibrium behavior as a function of time. We find this to be more generally fulfilled than in the scenario of the eigenstate thermalization hypothesis (ETH), namely for both local particle occupation numbers and non-local density correlation functions, and independent of the specific initial quantum state of the time evolution.
title Measurement-Induced Dynamical Quantum Thermalization
topic Quantum Physics
Quantum Gases
url https://arxiv.org/abs/2505.20593