Constructing Quantum Many-Body Scars from Hilbert Space Fragmentation

• URL: http://arxiv.org/abs/2506.10806v2
• Date: Tue, 22 Jul 2025 12:50:20 GMT
• Title: Constructing Quantum Many-Body Scars from Hilbert Space Fragmentation
• Authors: Fan Yang, Matteo Magoni, Hannes Pichler,
• Abstract summary: Quantum many-body scars (QMBS) are exotic many-body states that exhibit anomalous non-thermal behavior.<n>We show that exact QMBS can be constructed by injecting a quasiparticle that partially activates the frozen regions in the lattice.<n>Our findings establish direct connections between quantum many-body scarring and Hilbert space fragmentation, paving the way for systematically constructing exact and approximate QMBS.
• Score: 2.7204116565403744
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Quantum many-body scars (QMBS) are exotic many-body states that exhibit anomalous non-thermal behavior in an otherwise ergodic system. In this work, we demonstrate a simple, scalable and intuitive construction of QMBS in a kinetically constrained quantum model exhibiting weak Hilbert space fragmentation. We show that exact QMBS can be constructed by injecting a quasiparticle that partially activates the frozen regions in the lattice. Meanwhile, the inelastic collision between multiple quasiparticles allows for the construction of approximate scars, whose damping is governed by an emergent two-body loss. Our findings establish direct connections between quantum many-body scarring and Hilbert space fragmentation, paving the way for systematically constructing exact and approximate QMBS with nontrivial spatial connectivity. The proposed model can be readily implemented in neutral-atom quantum simulators aided by strong Rydberg interactions.

Related papers

• Topological crystals and soliton lattices in a Gross-Neveu model with Hilbert-space fragmentation [41.94295877935867]
  We explore the finite-density phase diagram of the single-flavour Gross-Neveu-Wilson (GNW) model.<n>We find a sequence of inhomogeneous ground states that arise through a real-space version of the mechanism of Hilbert-space fragmentation.
  arXiv  Detail & Related papers  (2025-06-23T14:19:35Z)
• Zero-energy Quantum Many-Body Scar under Emergent Chiral Symmetry and Pseudo Hilbert Space Fragmentation [3.688427498755018]
  We study the phenomenology of the zero-energy QMBS under the interplay between the chiral symmetry and pseudo HSF.<n>We find that the interplay between the two gives rise to a highly localized zero-energy QMBS when the particle number is even.<n>We identify a simple product state to signalize the zero-energy QMBS, which gives rise to unusual scarred dynamics.
  arXiv  Detail & Related papers  (2024-10-30T07:46:10Z)
• Origin of Hilbert space quantum scars in unconstrained models [9.063667511831522]
  Quantum many-body scar is a recently discovered phenomenon weakly violating eigenstate thermalization hypothesis. We study a distinct class of quantum many-body scars based on a half-filling hard-core Bose-Hubbard model.
  arXiv  Detail & Related papers  (2023-07-25T07:25:14Z)
• Neural-network quantum states for ultra-cold Fermi gases [49.725105678823915]
  This work introduces a novel Pfaffian-Jastrow neural-network quantum state that includes backflow transformation based on message-passing architecture. We observe the emergence of strong pairing correlations through the opposite-spin pair distribution functions. Our findings suggest that neural-network quantum states provide a promising strategy for studying ultra-cold Fermi gases.
  arXiv  Detail & Related papers  (2023-05-15T17:46:09Z)
• Overlapping qubits from non-isometric maps and de Sitter tensor networks [41.94295877935867]
  We show that processes in local effective theories can be spoofed with a quantum system with fewer degrees of freedom. We highlight how approximate overlapping qubits are conceptually connected to Hilbert space dimension verification, degree-of-freedom counting in black holes and holography.
  arXiv  Detail & Related papers  (2023-04-05T18:08:30Z)
• Robust quantum many-body scars in the one-dimensional spin-1 Kitaev model [0.0]
  Quantum many-body scars (QMBS) are a new paradigm for ergodicity-breaking. QMBSs can arise in one such model, namely the spin-$1$ Kitaev chain. We numerically demonstrate that its fidelity revivals are robust and longer-lived than those in the PXP model.
  arXiv  Detail & Related papers  (2023-03-07T21:57:33Z)
• Many-body Hilbert space scarring on a superconducting processor [19.205729719781548]
  Quantum many-body scarring (QMBS) is a recently discovered form of weak ergodicity breaking in strongly-interacting quantum systems. Here, we experimentally realize a distinct kind of QMBS phenomena by approximately decoupling a part of the many-body Hilbert space in the computational basis. Our experimental findings broaden the realm of QMBS mechanisms and pave the way to exploiting correlations in QMBS states for applications in quantum information technology.
  arXiv  Detail & Related papers  (2022-01-10T16:33:38Z)
• Quantum Many-Body Scars and Hilbert Space Fragmentation: A Review of Exact Results [0.0]
  Quantum Many-Body Scars (QMBS) have shown that a weak violation of ergodicity can lead to rich experimental and theoretical physics. We provide a pedagogical introduction to and an overview of the exact results on weak ergodicity breaking via QMBS in isolated quantum systems. We also review Hilbert Space Fragmentation, a related phenomenon where systems exhibit a richer variety of ergodic and non-ergodic behaviors.
  arXiv  Detail & Related papers  (2021-09-01T18:00:02Z)
• Controlling many-body dynamics with driven quantum scars in Rydberg atom arrays [41.74498230885008]
  We experimentally investigate non-equilibrium dynamics following rapid quenches in a many-body system composed of 3 to 200 strongly interacting qubits in one and two spatial dimensions. We discover that scar revivals can be stabilized by periodic driving, which generates a robust subharmonic response akin to discrete time-crystalline order.
  arXiv  Detail & Related papers  (2020-12-22T19:00:02Z)
• Exact many-body scars and their stability in constrained quantum chains [55.41644538483948]
  Quantum scars are non-thermal eigenstates characterized by low entanglement entropy. We study the response of these exact quantum scars to perturbations by analysing the scaling of the fidelity susceptibility with system size.
  arXiv  Detail & Related papers  (2020-11-16T19:05:50Z)
• Dynamical solitons and boson fractionalization in cold-atom topological insulators [110.83289076967895]
  We study the $mathbbZ$ Bose-Hubbard model at incommensurate densities. We show how defects in the $mathbbZ$ field can appear in the ground state, connecting different sectors. Using a pumping argument, we show that it survives also for finite interactions.
  arXiv  Detail & Related papers  (2020-03-24T17:31:34Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.