Decay and recurrence of non-Gaussian correlations in a quantum many-body system

Schweigler, Thomas (avtor), Sotiriadis, Spyros (avtor)

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.

• Jezik: Angleški jezik
• Ključne besede: statistical physics, quantum mechanics
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FMF - Fakulteta za matematiko in fiziko
• Status publikacije: Objavljeno
• Različica publikacije: Recenzirani rokopis
• Leto izida: 2021
• Št. strani: Str. 559-563
• Številčenje: Vol. 17, iss. 5
• PID: 20.500.12556/RUL-132290
• UDK: 530.145
• ISSN pri članku: 1745-2473
• DOI: 10.1038/s41567-020-01139-2
• COBISS.SI-ID: 62640131
• Datum objave v RUL: 20.10.2021

Gradivo je del revije

• Naslov: Nature physics
• Založnik: Nature Pub.
• ISSN: 1745-2473
• COBISS.SI-ID: 23900455

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: statistična fizika, kvantna mehanika

Projekti

• Financer: EC - European Commission
• Program financ.: H2020
• Številka projekta: 694544
• Naslov: Open Many-body Non-Equilibrium Systems
• Akronim: OMNES

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: N1-0109
• Naslov: Kvantni sunki, transport in prepletenost v neravnovesnih enodimenzionalnih kvantnih sistemih