Relaxation of imbalance in a disordered XX model with on-site dephasing

Ghosh, Roopayan (author), Žnidarič, Marko (author)

The relaxation of observables to their nonequilibrium steady states in a disordered XX chain subjected to dephasing at every site has been intensely studied in recent years. We comprehensively analyze the relaxation of staggered magnetization, i.e., imbalance, in such a system, starting from the Néel initial state. We analytically predict emergence of several timescales in the system and extract results which match with large-system numerics without any extra fitting parameter until a universal timescale. An often reported stretched exponential decay is just one of the regimes which holds in a finite window of time and is therefore in fact not a true stretched exponential decay. Subsequently, the asymptotic decay of imbalance is governed by a power law irrespective of the disorder. We show that this emerges from the continuum limit of the low magnitude eigenspectrum of the Liouvillian. However, for finite systems, due to discreteness of the spectrum, the final phase of relaxation is governed by the relevant smallest Liouvillian gap.

• Language: English
• Keywords: condensed matter physics, disordered systems, open quantum systems
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication version: Version of Record
• Publication date: 04.05.2023
• Year: 2023
• Number of pages: Str. 184303-1-184303-14
• Numbering: Vol. 107, iss. 18
• PID: 20.500.12556/RUL-155020
• UDC: 538.9
• ISSN on article: 2469-9950
• DOI: 10.1103/PhysRevB.107.184303
• COBISS.SI-ID: 188915203
• Publication date in RUL: 14.03.2024

Record is a part of a journal

• Title: Physical review
• Publisher: American Physical Society
• ISSN: 2469-9950
• COBISS.SI-ID: 2997348

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: fizika kondenzirane snovi, neurejeni sistemi, odprti kvantni sistemi