State-dependent mobility edge in kinetically constrained models

• URL: http://arxiv.org/abs/2407.12909v2
• Date: Wed, 25 Dec 2024 10:14:04 GMT
• Title: State-dependent mobility edge in kinetically constrained models
• Authors: Manthan Badbaria, Nicola Pancotti, Rajeev Singh, Jamir Marino, Riccardo J. Valencia-Tortora,
• Abstract summary: We show that the kinetically constrained quantum East model lies between a quantum scarred and a many-body localized system.<n>We name this scenario $textitstate-dependent$ mobility edge: while the system does not exhibit a sharp separation in energy between thermal and non-thermal eigenstates, the abundance of non-thermal eigenstates results in slow entanglement growth.
• Score: 0.2796197251957244
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: In this work, we show that the kinetically constrained quantum East model lies between a quantum scarred and a many-body localized system featuring an unconventional type of mobility edge in the spectrum. We name this scenario $\textit{state-dependent}$ mobility edge: while the system does not exhibit a sharp separation in energy between thermal and non-thermal eigenstates, the abundance of non-thermal eigenstates results in slow entanglement growth for $\textit{many}$ initial states, such as product states, below a finite energy density. We characterize the state-dependent mobility edge by looking at the complexity of classically simulating dynamics using tensor network for system sizes well beyond those accessible via exact diagonalization. Focusing on initial product states, we observe a qualitative change in the dynamics of the bond dimension needed as a function of their energy density. Specifically, the bond dimension typically grows $\textit{polynomially}$ in time up to a certain energy density, where we locate the state-dependent mobility edge, enabling simulations for long times. Above this energy density, the bond dimension typically grows $\textit{exponentially}$ making the simulation practically unfeasible beyond short times, as generally expected in interacting theories. We correlate the polynomial growth of the bond dimension to the presence of many non-thermal eigenstates around that energy density, a subset of which we compute via tensor network. The outreach of our findings encompasses quantum sampling problems and the efficient simulation of quantum circuits beyond Clifford families.

Related papers

• Excitation transfer and many-body dark states in WQED [4.608193506134334]
  In one-dimensional waveguide quantum electrodynamics systems, quantum emitters interact through infinite-range, dispersive, and dissipative dipole-dipole interactions. These interactions give rise to long-range periodic behavior and rich many-body physics absent in free space. We construct a set of symmetrized M-excitation dark states and derive analytic expressions for their time-evolution projections.
  arXiv  Detail & Related papers  (2025-04-17T06:07:22Z)
• Dipole-dipole interactions mediated by a photonic flat band [44.99833362998488]
  We study the photon-dipole interactions between emitters dispersively coupled to the photonic analogue of a flat band (FB) We show that the strength of such photon-mediated interactions decays exponentially with distance with a characteristic localization length. We find that the localization length grows with the overlap between CLSs according to an analytically-derived universal scaling law valid for a large class of FBs both in 1D and 2D.
  arXiv  Detail & Related papers  (2024-05-30T18:00:05Z)
• Thermalization and Criticality on an Analog-Digital Quantum Simulator [133.58336306417294]
  We present a quantum simulator comprising 69 superconducting qubits which supports both universal quantum gates and high-fidelity analog evolution. We observe signatures of the classical Kosterlitz-Thouless phase transition, as well as strong deviations from Kibble-Zurek scaling predictions. We digitally prepare the system in pairwise-entangled dimer states and image the transport of energy and vorticity during thermalization.
  arXiv  Detail & Related papers  (2024-05-27T17:40:39Z)
• Quantum simulation of entanglement and hadronization in jet production: lessons from the massive Schwinger model [0.0]
  We study the real-time response of the massive Schwinger model coupled to external sources. By using quantum simulations on classical hardware, we study the entanglement between the produced jets. We observe the transition from fermionic Fock states to meson-like bound states as a function of time.
  arXiv  Detail & Related papers  (2024-03-29T18:00:00Z)
• Non-thermal eigenstates and slow relaxation in quantum Fredkin spin chains [0.0]
  We study the dynamics and thermalization of the Fredkin spin chain, a system with local three-body interactions. We consider deformations away from its point in order to tune between regimes where kinetic energy dominates those where potential energy does.
  arXiv  Detail & Related papers  (2024-03-06T19:00:16Z)
• Observation of a finite-energy phase transition in a one-dimensional quantum simulator [39.899531336700136]
  We show the first experimental demonstration of a finite-energy phase transition in 1D. By preparing initial states with different energies in a 1D trapped-ion quantum simulator, we study the finite-energy phase diagram of a long-range interacting quantum system.
  arXiv  Detail & Related papers  (2023-10-30T18:00:01Z)
• Message-Passing Neural Quantum States for the Homogeneous Electron Gas [41.94295877935867]
  We introduce a message-passing-neural-network-based wave function Ansatz to simulate extended, strongly interacting fermions in continuous space. We demonstrate its accuracy by simulating the ground state of the homogeneous electron gas in three spatial dimensions.
  arXiv  Detail & Related papers  (2023-05-12T04:12:04Z)
• Universality of critical dynamics with finite entanglement [68.8204255655161]
  We study how low-energy dynamics of quantum systems near criticality are modified by finite entanglement. Our result establishes the precise role played by entanglement in time-dependent critical phenomena.
  arXiv  Detail & Related papers  (2023-01-23T19:23:54Z)
• Exact universal bounds on quantum dynamics and fast scrambling [0.0]
  We show that the spectral form factor sets a universal state-independent bound on the quantum dynamics of a complete set of initial states over arbitrarily long times. We use this result to constrain the scrambling of information in interacting many-body systems.
  arXiv  Detail & Related papers  (2022-12-28T18:47:20Z)
• Superdiffusive Energy Transport in Kinetically Constrained Models [0.0]
  We study infinite-temperature energy transport in the kinetically-constrained PXP model describing Rydberg atom quantum simulators. Our results suggest constrained models to be potential hosts of novel transport regimes.
  arXiv  Detail & Related papers  (2022-10-03T18:00:22Z)
• Formation of robust bound states of interacting microwave photons [148.37607455646454]
  One of the hallmarks of interacting systems is the formation of multi-particle bound states. We develop a high fidelity parameterizable fSim gate that implements the periodic quantum circuit of the spin-1/2 XXZ model. By placing microwave photons in adjacent qubit sites, we study the propagation of these excitations and observe their bound nature for up to 5 photons.
  arXiv  Detail & Related papers  (2022-06-10T17:52:29Z)
• Kinetically Constrained Quantum Dynamics in Superconducting Circuits [0.7734726150561088]
  We study the dynamical properties of the bosonic quantum East model at low temperature. We show that quantum information remains localized within decoherence times tunable with the parameters of the system. We propose an implementation of the bosonic quantum East model based on state-of-the-art superconducting circuits.
  arXiv  Detail & Related papers  (2021-12-15T19:00:02Z)
• Fast Thermalization from the Eigenstate Thermalization Hypothesis [69.68937033275746]
  Eigenstate Thermalization Hypothesis (ETH) has played a major role in understanding thermodynamic phenomena in closed quantum systems. This paper establishes a rigorous link between ETH and fast thermalization to the global Gibbs state. Our results explain finite-time thermalization in chaotic open quantum systems.
  arXiv  Detail & Related papers  (2021-12-14T18:48:31Z)
• Observation of Time-Crystalline Eigenstate Order on a Quantum Processor [80.17270167652622]
  Quantum-body systems display rich phase structure in their low-temperature equilibrium states. We experimentally observe an eigenstate-ordered DTC on superconducting qubits. Results establish a scalable approach to study non-equilibrium phases of matter on current quantum processors.
  arXiv  Detail & Related papers  (2021-07-28T18:00:03Z)
• Long-lived period-doubled edge modes of interacting and disorder-free Floquet spin chains [68.8204255655161]
  We show that even in the absence of disorder, and in the presence of bulk heating, $pi$ edge modes are long lived. A tunneling estimate for the lifetime is obtained by mapping the stroboscopic time-evolution to dynamics of a single particle in Krylov subspace.
  arXiv  Detail & Related papers  (2021-05-28T12:13:14Z)
• Probing eigenstate thermalization in quantum simulators via fluctuation-dissipation relations [77.34726150561087]
  The eigenstate thermalization hypothesis (ETH) offers a universal mechanism for the approach to equilibrium of closed quantum many-body systems. Here, we propose a theory-independent route to probe the full ETH in quantum simulators by observing the emergence of fluctuation-dissipation relations. Our work presents a theory-independent way to characterize thermalization in quantum simulators and paves the way to quantum simulate condensed matter pump-probe experiments.
  arXiv  Detail & Related papers  (2020-07-20T18:00:02Z)

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.