Abstract

Gaussian models provide an excellent effective description of many quantum many-body systems ranging from condensed-matter systems all the way to neutron stars. Gaussian states are common at equilibrium when the interactions are weak. Recently it was proposed that they can also emerge dynamically from a non-Gaussian initial state evolving under non-interacting dynamics. Here we present the experimental observation of such a dynamical emergence of Gaussian correlations in a quantum many-body system. This non-equilibrium evolution is triggered by abruptly switching off the effective interaction between the observed collective degrees of freedom, while leaving the interactions between the microscopic constituents unchanged. Starting from highly non-Gaussian correlations, consistent with the sine–Gordon model, we observe a Gaussian state emerging over time as revealed by the decay of the fourth- and sixth-order connected correlations in the quantum field. A description of this dynamics requires a novel mechanism for the emergence of Gaussian correlations, which is relevant for a wide class of quantum many-body systems. In our closed system with non-interacting effective degrees of freedom, we do not expect full thermalization. This memory of the initial state is confirmed by observing recurrences of non-Gaussian correlations.

Keywords

statistična fizika;kvantna mehanika;statistical physics;quantum mechanics;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UL FMF - Faculty of Mathematics and Physics
UDC: 530.145
COBISS: 62640131 Link will open in a new window
ISSN: 1745-2473
Views: 180
Downloads: 95
Average score: 0 (0 votes)
Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: Slovenian
Secondary keywords: statistična fizika;kvantna mehanika;
Embargo end date (OpenAIRE): 2021-07-18
Pages: str. 559-563
Volume: ǂVol. ǂ17
Issue: ǂiss. ǂ5
Chronology: 2021
DOI: 10.1038/s41567-020-01139-2
ID: 13723046