Year: 2018
Type: article
Abstract: Under unitary time evolution, expectation values of physically reasonable observables often evolve towards the predictions of equilibrium statistical mechanics. The eigenstate thermalization hypothesis (ETH) states that this is also true already for individual energy eigenstates. Here we aim at elucidating the emergence of the ETH for observables that can realistically be measured due to their high degeneracy, such as local, extensive, or macroscopic observables. We bisect this problem into two parts, a condition on the relative overlaps and one on the relative phases between the eigenbases of the observable and Hamiltonian. We show that the relative overlaps are unbiased for highly degenerate observables and demonstrate that unless relative phases conspire to cumulative effects, this makes such observables verify the ETH. Through this we elucidate potential pathways towards proofs of thermalization.
Source: Physical Review Letters
Authors: Fabio Anza, Christian Gogolin, Marcus Huber
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: Fondazione Angelo Della Riccia, Fundación Cellex, St. Catherine's College, University of Oxford, European Cooperation in Science and Technology, Austrian Science Fund, Generalitat de Catalunya, Ministerio de Economía y Competitividad, Narodowe Centrum Nauki, Seventh Framework Programme, Agència de Gestió d'Ajuts Universitaris i de Recerca, H2020 European Research Council, H2020 Marie Skłodowska-Curie Actions
OpenAlex ID: W2742646981