Measurement Induced Continuous Time Crystals

• URL: http://arxiv.org/abs/2206.14438v1
• Date: Wed, 29 Jun 2022 07:24:27 GMT
• Title: Measurement Induced Continuous Time Crystals
• Authors: Midhun Krishna, Parvinder Solanki, Michal Hajdu\v{s}ek and Sai Vinjanampathy
• Abstract summary: We show that the magnetization of the thermodynamically large ancilla spins develops limit cycle oscillations. Our result also demonstrates that a coherent drive is not necessary in order to induce continuous time-translation symmetry breaking.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Strong measurements usually restrict the dynamics of measured finite dimensional systems to the Zeno subspace, where subsequent evolution is unitary due to the suppression of dissipative terms. Here we show qualitatively different behaviour due to the competition between strong measurements and the thermodynamic limit, inducing a time-translation symmetry breaking phase transition resulting in a continuous time crystal. We consider a spin star model, where the central spin is subject to a strong continuous measurement, and qualify the dynamic behaviour of the system in various parameter regimes. We show that above a critical value of measurement strength, the magnetization of the thermodynamically large ancilla spins develops limit cycle oscillations. Our result also demonstrates that a coherent drive is not necessary in order to induce continuous time-translation symmetry breaking.

Related papers

• Measurement-induced transitions for interacting fermions [43.04146484262759]
  We develop a field-theoretical framework that provides a unified approach to observables characterizing entanglement and charge fluctuations. Within this framework, we derive a replicated Keldysh non-linear sigma model (NLSM) By using the renormalization-group approach for the NLSM, we determine the phase diagram and the scaling of physical observables.
  arXiv  Detail & Related papers  (2024-10-09T18:00:08Z)
• Measurement-induced entanglement transition in chaotic quantum Ising chain [42.87502453001109]
  We study perturbations that break the integrability and/or the symmetry of the model, as well as modifications in the measurement protocol, characterizing the resulting chaos and lack of integrability through the Dissipative Spectral Form Factor (DSFF) We show that while the measurement-induced phase transition and its properties appear broadly insensitive to lack of integrability and breaking of the $bbZ$ symmetry, a modification of the measurement basis from the transverse to the longitudinal direction makes the phase transition disappear altogether.
  arXiv  Detail & Related papers  (2024-07-11T17:39:29Z)
• Motion from Measurement: The Role of Symmetry of Quantum Measurements [0.0]
  We consider the dependence on the measurement rate and find that the current is non-monotonic. Nondegenerate measurements can lead to current loops within the steady state even in the Zeno limit.
  arXiv  Detail & Related papers  (2024-05-09T17:35:49Z)
• Emergent Continuous Time Crystal in Dissipative Quantum Spin System without Driving [1.641189223782504]
  Time crystal, a nonequilibrium phenomenon extending spontaneous symmetry breaking into the temporal dimension, holds fundamental significance in quantum many-body physics. We numerically identify the emergence of novel nonstationary oscillatory states by analyzing the spin dynamics. This study provides many insights into the intricate interplay between the dissipation-induced spin downwards and anisotropic-interaction-induced spin precession or spin fluctuation.
  arXiv  Detail & Related papers  (2024-03-13T12:40:32Z)
• Slow semiclassical dynamics of a two-dimensional Hubbard model in disorder-free potentials [77.34726150561087]
  We show that introduction of harmonic and spin-dependent linear potentials sufficiently validates fTWA for longer times. In particular, we focus on a finite two-dimensional system and show that at intermediate linear potential strength, the addition of a harmonic potential and spin dependence of the tilt, results in subdiffusive dynamics.
  arXiv  Detail & Related papers  (2022-10-03T16:51:25Z)
• Indication of critical scaling in time during the relaxation of an open quantum system [34.82692226532414]
  Phase transitions correspond to the singular behavior of physical systems in response to continuous control parameters like temperature or external fields. Near continuous phase transitions, associated with the divergence of a correlation length, universal power-law scaling behavior with critical exponents independent of microscopic system details is found.
  arXiv  Detail & Related papers  (2022-08-10T05:59:14Z)
• Clean two-dimensional Floquet time-crystal [68.8204255655161]
  We consider the two-dimensional quantum Ising model, in absence of disorder, subject to periodic imperfect global spin flips. We show by a combination of exact diagonalization and tensor-network methods that the system can sustain a spontaneously broken discrete time-translation symmetry. We observe a non-perturbative change in the decay rate of the order parameter, which is related to the long-lived stability of the magnetic domains in 2D.
  arXiv  Detail & Related papers  (2022-05-10T13:04:43Z)
• Harmonic oscillator kicked by spin measurements: a Floquet-like system without classical analogous [62.997667081978825]
  The impulsive driving is provided by stroboscopic measurements on an ancillary degree of freedom. The dynamics of this system is determined in closed analytical form. We observe regimes with crystalline and quasicrystalline structures in phase space, resonances, and evidences of chaotic behavior.
  arXiv  Detail & Related papers  (2021-11-23T20:25:57Z)
• 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)
• Diagnosing entanglement dynamics in noisy and disordered spin chains via the measurement-induced steady-state entanglement transition [0.0]
  We analyze the interplay and competition of processes that generate and destroy entanglement in a one-dimensional quantum spin chain under a noisy Hamiltonian. Our results establish a firm connection between this entanglement growth and the steady-state behavior of the measurement-controlled systems.
  arXiv  Detail & Related papers  (2021-07-23T17:16:48Z)

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.