Ergodicity breaking transition in finite disordered spin chains

Šuntajs, Jan (author), Bonča, Janez (author), Prosen, Tomaž (author), Vidmar, Lev (author)

We study disorder-induced ergodicity breaking transition in high-energy eigenstates of interacting spin-1/2 chains. Using exact diagonalization, we introduce a cost function approach to quantitatively compare different scenarios for the eigenstate transition. We study ergodicity indicators such as the eigenstate entanglement entropy and the spectral level spacing ratio, and we consistently find that an (infinite-order) Berezinskii-KosterlitzThouless transition yields a lower cost function when compared to a finite-order transition. Interestingly, we observe that the ergodicity breaking transition in systems studied by exact diagonalization (with around 20 lattice sites) takes place at disorder values lower than those reported in previous works. As a consequence, the crossing point in finite systems exhibits nearly thermal properties, i.e., ergodicity indicators at the transition are close to the random matrix theory predictions.

• Language: English
• Keywords: quantum statistical mechanics
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Year: 2020
• Number of pages: Str. 064207-1-064207-11
• Numbering: Vol. 102, iss. 6
• PID: 20.500.12556/RUL-118047
• UDC: 536.93
• ISSN on article: 2469-9950
• DOI: 10.1103/PhysRevB.102.064207
• COBISS.SI-ID: 25337091
• Publication date in RUL: 17.08.2020

Record is a part of a journal

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

Secondary language

• Language: Slovenian
• Keywords: kvantna statistična mehanika