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Related papers: Alternatives to Eigenstate Thermalization

200 papers

We provide a pedagogical introduction to eigenstate thermalization. This phenomenon, which occurs in generic quantum systems, allows one to understand why thermalization takes place in isolated systems under unitary dynamics. We motivate…

Quantum Physics · Physics 2026-04-29 Rohit Patil , Marcos Rigol

Motivated by the qualitative picture of Canonical Typicality, we propose a refined formulation of the Eigenstate Thermalization Hypothesis (ETH) for chaotic quantum systems. The new formulation, which we refer to as subsystem ETH, is in…

Statistical Mechanics · Physics 2018-04-06 Anatoly Dymarsky , Nima Lashkari , Hong Liu

This work investigates the relationship between quantum chaos and thermalization in a three-species Bose-Josephson Junction (BJJ) with mutual interactions, without coupling to any external environment. The analysis is grounded in the…

Statistical Mechanics · Physics 2026-04-21 Francesco Di Menna , Sergio Ciuchi , Simone Paganelli

We explore the role of the initial state on the onset of thermalization in isolated quantum many-body systems after a quench. The initial state is an eigenstate of an initial Hamiltonian $\hat{H}_I$ and it evolves according to a different…

Statistical Mechanics · Physics 2013-10-16 E. J. Torres-Herrera , Lea F. Santos

Eigenstate thermalization refers to the property that an energy eigenstate of a many-body system is indistinguishable from a thermal equilibrium ensemble at the same energy as far as expectation values of local observables are concerned. In…

Statistical Mechanics · Physics 2026-03-25 Lennart Dabelow , Christian Eidecker-Dunkel , Peter Reimann

We verify that the eigenstate thermalization hypothesis (ETH) holds universally for locally interacting quantum many-body systems. Introducing random-matrix ensembles with interactions, we numerically obtain a distribution of maximum…

Statistical Mechanics · Physics 2021-03-31 Shoki Sugimoto , Ryusuke Hamazaki , Masahito Ueda

The eigenstate thermalization hypothesis (ETH) provides a fundamental mechanism for emergent statistical mechanics in isolated chaotic quantum systems, asserting that individual energy eigenstates behave as pseudorandom vectors within an…

Quantum Physics · Physics 2026-05-27 Ning Sun , Yanting Cheng

Thermalization of a closed chaotic quantum system is commonly addressed in terms of the eigenstate thermalization hypothesis (ETH). An alternative approach uses the Bohigas-Giannoni-Schmit (BGS) conjecture. The comparison shows that the two…

Mathematical Physics · Physics 2025-09-29 Hans A. Weidenmüller

The eigenstate thermalization hypothesis (ETH) is a conjecture on the nature of isolated quantum systems that guarantees the thermal behavior of subsystems when it is satisfied. ETH has been tested in various forms on a number of local…

Statistical Mechanics · Physics 2019-09-18 Masudul Haque , Paul McClarty

The Eigenstate Thermalization Hypothesis (ETH) explains emergence of the thermodynamic equilibrium by assuming a particular structure of observable's matrix elements in the energy eigenbasis. Schematically, it postulates that off-diagonal…

Statistical Mechanics · Physics 2022-05-11 Jiaozi Wang , Mats H. Lamann , Jonas Richter , Robin Steinigeweg , Anatoly Dymarsky , Jochen Gemmer

We show that a bounded, isolated quantum system of many particles in a specific initial state will approach thermal equilibrium if the energy eigenfunctions which are superposed to form that state obey {\it Berry's conjecture}. Berry's…

Condensed Matter · Physics 2009-10-22 Mark Srednicki

Based on the view that thermal equilibrium should be characterized through macroscopic observations, we develop a general theory about typicality of thermal equilibrium and the approach to thermal equilibrium in macroscopic quantum systems.…

Statistical Mechanics · Physics 2018-08-02 Hal Tasaki

Boltzmann's ergodic hypothesis furnishes a possible explanation for the emergence of statistical mechanics in the framework of classical physics. In quantum mechanics, the Eigenstate Thermalization Hypothesis (ETH) is instead generally…

Statistical Mechanics · Physics 2019-04-08 Lorenzo Campos Venuti , Lawrence Liu

In this article it will be introduced a new theorem, can be considered a generalization of Hellmann-Feynman theorem[1]. The latter used in conjunction with the quantization of the free energy[2] of a quantum system allows to derive…

Materials Science · Physics 2020-12-02 S. Selenu

In the present note, we discuss a simple example of a macroscopic quantum many-body system in which the approach to thermal equilibrium from an arbitrary initial state in the microcanonical energy shell is proved without relying on any…

Statistical Mechanics · Physics 2024-04-09 Hal Tasaki

A strongly non-integrable system is expected to satisfy the eigenstate thermalization hypothesis, which states that the expectation value of an observable in an energy eigenstate is the same as the thermal value. This must be revised if the…

Statistical Mechanics · Physics 2015-11-04 Keith R. Fratus , Mark Srednicki

Thermalization of isolated many-body systems is demonstrated by generalizing an approach originally due to von Neumann: For arbitrary initial states with a macroscopically well-defined energy, quantum mechanical expectation values become…

Statistical Mechanics · Physics 2015-07-02 Peter Reimann

We investigate the eigenstate thermalization hypothesis (ETH) for a translationally invariant quantum spin system on the $d$-dimensional cubic lattice under the periodic boundary conditions. It is known that the ETH holds in this model for…

Statistical Mechanics · Physics 2016-10-03 Takashi Mori

Ergodic isolated quantum many-body systems satisfy the eigenstate thermalization hypothesis (ETH), i.e., the expectation values of local observables in the system's eigenstates approach the predictions of the microcanonical ensemble.…

Disordered Systems and Neural Networks · Physics 2025-11-25 Adith Sai Aramthottil , Ali Emami Kopaei , Piotr Sierant , Lev Vidmar , Jakub Zakrzewski

The eigenstate thermalization hypothesis (ETH) has been highly influential in explaining thermodynamic behavior of closed quantum systems. As of yet, it is unclear whether and how the ETH applies to non-Hermitian systems. Here, we introduce…