Tunable Hilbert space fragmentation and extended critical regime
arXiv:2505.09346 · doi:10.1103/fysk-w1vs
Abstract
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 (SLIOM), 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 - 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.
References in corpus (56)
- Thermalization and its mechanism for generic isolated quantum systems
- From Quantum Chaos and Eigenstate Thermalization to Statistical Mechanics and Thermodynamics
- Relaxation in a Completely Integrable Many-Body Quantum System: An Ab Initio Study of the Dynamics of the Highly Excited States of Lattice Hard-Core Bosons
- Quantum many-body systems out of equilibrium
- Generalized Gibbs ensemble in integrable lattice models
- Eigenstate Thermalization Hypothesis
- Fidelity, dynamic structure factor, and susceptibility in critical phenomena
- Thermalization and prethermalization in isolated quantum systems: a theoretical overview
- Localization from Hilbert space shattering: from theory to physical realizations
- Local constraints can globally shatter Hilbert space: a new route to quantum information protection
- Ergodicity-breaking arising from Hilbert space fragmentation in dipole-conserving Hamiltonians
- Onset of quantum chaos in one-dimensional bosonic and fermionic systems and its relation to thermalization
- Geometry and non-adiabatic response in quantum and classical systems
- Generalized Gibbs ensemble prediction of prethermalization plateaus and their relation to nonthermal steady states in integrable systems
- Hard-core bosons on optical superlattices: Dynamics and relaxation in the superfluid and insulating regimes
- Prethermalization and thermalization in models with weak integrability breaking
- Ground-State Fidelity and Bipartite Entanglement in the Bose-Hubbard Model
- Fidelity susceptibility, scaling, and universality in quantum critical phenomena
- Off-diagonal matrix elements of local operators in many-body quantum systems
- Statistical localization: from strong fragmentation to strong edge modes
- Eigenstate thermalization within isolated spin-chain systems
- Intrinsic relation between ground-state fidelity and the characterization of a quantum phase transition
- Quantum phase transitions and quantum fidelity in free fermion graphs
- Adiabatic eigenstate deformations as a sensitive probe for quantum chaos
- Entanglement and matrix elements of observables in interacting integrable systems
- Prethermalization and Thermalization in Isolated Quantum Systems
- Quantum Monte Carlo simulations of fidelity at magnetic quantum phase transitions
- Eigenstate Thermalization in a Locally Perturbed Integrable System
- Transport in Almost Integrable Models: Perturbed Heisenberg Chains
- Scaling Theory of Entanglement at the Many-Body Localization Transition
- Global characteristics of all eigenstates of local many-body Hamiltonians: participation ratio and entanglement entropy
- Level statistics across the many--body localization transition
- Fidelity susceptibility made simple: A unified quantum Monte Carlo approach
- Low-frequency behavior of off-diagonal matrix elements in the integrable XXZ chain and in a locally perturbed quantum-chaotic XXZ chain
- Eigenstate thermalization hypothesis and integrals of motion
- Entanglement in ground and excited states of gapped fermion systems and their relationship with fermi surface and thermodynamic equilibrium properties
- Eigenstate thermalization hypothesis through the lens of autocorrelation functions
- Fidelity Susceptibility in One-dimensional Disordered Lattice Models
- Scaling of electrical and thermal conductivities in an almost integrable chain
- Hilbert space fragmentation and slow dynamics in particle-conserving quantum East models
- Eigenstate thermalization for observables that break Hamiltonian symmetries and its counterpart in interacting integrable systems
- Phenomenology of spectral functions in disordered spin chains at infinite temperature
- Fidelity susceptibility in Gaussian Random Ensembles
- Weak integrability breaking perturbations of integrable models
- Adiabatic eigenstate deformations and weak integrability breaking of Heisenberg chain
- Weak integrability breaking and level spacing distribution
- Singular Solutions to the Bethe Ansatz Equations and Rigged Configurations
- Hilbert space fragmentation in a long-range system
- Probing the edge between integrability and quantum chaos in interacting few-atom systems
- Normal weak eigenstate thermalization
- Integrability as an attractor of adiabatic flows
- Multiple relaxation times in perturbed XXZ chain
- Subspace restricted thermalization in a correlated-hopping model with strong Hilbert space fragmentation characterized by irreducible strings
- Long-living prethermalization in nearly integrable spin ladders
- Adiabatic gauge potential and integrability breaking with free fermions
- Local integrals of motion in dipole-conserving models with Hilbert space fragmentation