20.500.12556/RUL-176181 Tunable Hilbert space fragmentation and extended critical regime 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. eigenstate thermalization strongly correlated systems integrable systems exact diagonalization termalizacija lastnih stanj močno korelirani sistemi integrabilni sistemi točna diagonalizacija true false true Angleški jezik Slovenski jezik Članek v reviji 2025-11-24 11:40:25 2025-11-24 11:40:26 2025-11-25 04:32:49 0000-00-00 00:00:00 2025 0 0 Str. 195116-1-195116-11 iss. 19 Vol. 112 2025 0000-00-00 PostprintKoncna Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 538.9 2469-9950 10.1103/fysk-w1vs 258339843 2505.09346v2.pdf 2505.09346v2.pdf 1 D9191EB90E6EE6E5C625C591BDCA9E87 6bf5a01d7528704640bb5cf7849da76baf059f79f06534091990ba99ecef1e8e 5fda460c-c922-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=222428 https://journals.aps.org/prb/abstract/10.1103/fysk-w1vs 0 37b9bded-c922-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=222427 Fakulteta za matematiko in fiziko 0 0 0