Tunable Hilbert space fragmentation and extended critical regime

Lisiecki, Mateusz (avtor), Bonča, Janez (avtor), Mierzejewski, Marcin (avtor), Herbrych, Jacek (avtor), Łydżba, Patrycja (avtor)

Systems exhibiting the Hilbert-space fragmentation are nonergodic, and their Hamiltonians decompose into exponentially many blocks in the computational basis. In many cases, these blocks can be labeled by eigenvalues of statistically localized integrals of motion (SLIOMs), which play a similar role in fragmented systems as local integrals of motion in integrable systems. While a nonzero perturbation eliminates all nontrivial conserved quantities from integrable models, we demonstrate for the $t$-$J_\mathrm{z}$ chain that an appropriately chosen perturbation may gradually eliminate SLIOMs (one by one) by progressively merging the fragmented subspaces. This gradual recovery of ergodicity manifests as an extended critical regime characterized by multiple peaks of the fidelity susceptibility. Each peak signals a change in the number of SLIOMs and blocks, as well as an ultra-slow relaxation of local observables.

• Jezik: Angleški jezik
• Ključne besede: eigenstate thermalization, strongly correlated systems, integrable systems, exact diagonalization
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FMF - Fakulteta za matematiko in fiziko
• Status publikacije: Objavljeno
• Različica publikacije: Recenzirani rokopis
• Leto izida: 2025
• Št. strani: Str. 195116-1-195116-11
• Številčenje: Vol. 112, iss. 19
• PID: 20.500.12556/RUL-176181
• UDK: 538.9
• ISSN pri članku: 2469-9950
• DOI: 10.1103/fysk-w1vs
• COBISS.SI-ID: 258339843
• Datum objave v RUL: 24.11.2025

Gradivo je del revije

• Naslov: Physical review
• Založnik: American Physical Society
• ISSN: 2469-9950
• COBISS.SI-ID: 2997348

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: termalizacija lastnih stanj, močno korelirani sistemi, integrabilni sistemi, točna diagonalizacija