Critical phase and spin sharpening in SU(2)-symmetric monitored quantum circuits

• URL: http://arxiv.org/abs/2305.13356v3
• Date: Sat, 19 Aug 2023 18:04:22 GMT
• Title: Critical phase and spin sharpening in SU(2)-symmetric monitored quantum circuits
• Authors: Shayan Majidy, Utkarsh Agrawal, Sarang Gopalakrishnan, Andrew C. Potter, Romain Vasseur, Nicole Yunger Halpern
• Abstract summary: We study SU(2)-symmetric monitored quantum circuits. We find a transition between a volume-law entangled phase and a critical phase. We numerically identify a "spin-sharpening transition"
• Score: 1.188383832081829
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Monitored quantum circuits exhibit entanglement transitions at certain measurement rates. Such a transition separates phases characterized by how much information an observer can learn from the measurement outcomes. We study SU(2)-symmetric monitored quantum circuits, using exact numerics and a mapping onto an effective statistical-mechanics model. Due to the symmetry's non-Abelian nature, measuring qubit pairs allows for nontrivial entanglement scaling even in the measurement-only limit. We find a transition between a volume-law entangled phase and a critical phase whose diffusive purification dynamics emerge from the non-Abelian symmetry. Additionally, we numerically identify a "spin-sharpening transition." On one side is a phase in which the measurements can efficiently identify the system's total spin quantum number; on the other side is a phase in which measurements cannot.

Related papers

• Charge and Spin Sharpening Transitions on Dynamical Quantum Trees [0.027042267806481293]
  We study entanglement and sharpening transitions in monitored quantum trees obeying U (1) and SU (2) symmetries. We find that the entanglement/purification and sharpening transitions generically occur at distinct measurement rates. In the SU (2) case, we find that the fuzzy phase is generic, and a sharp phase is possible only in the limit of maximal measurement rate.
  arXiv  Detail & Related papers  (2024-05-22T18:06:15Z)
• Quantum metric and metrology with parametrically-driven Tavis-Cummings models [4.419622364505575]
  We study the quantum metric in a driven Tavis-Cummings model, comprised of multiple qubits interacting with a quantized photonic field. We analytically solved the eigenenergies and eigenstates, and numerically simulated the system behaviors near the critical point.
  arXiv  Detail & Related papers  (2023-12-13T14:20:03Z)
• Quantifying measurement-induced quantum-to-classical crossover using an open-system entanglement measure [49.1574468325115]
  We study the entanglement of a single particle under continuous measurements. We find that the entanglement at intermediate time scales shows the same qualitative behavior as a function of the measurement strength.
  arXiv  Detail & Related papers  (2023-04-06T09:45:11Z)
• Evolution of many-body systems under ancilla quantum measurements [58.720142291102135]
  We study the concept of implementing quantum measurements by coupling a many-body lattice system to an ancillary degree of freedom. We find evidence of a disentangling-entangling measurement-induced transition as was previously observed in more abstract models.
  arXiv  Detail & Related papers  (2023-03-13T13:06:40Z)
• Geometric phases along quantum trajectories [58.720142291102135]
  We study the distribution function of geometric phases in monitored quantum systems. For the single trajectory exhibiting no quantum jumps, a topological transition in the phase acquired after a cycle. For the same parameters, the density matrix does not show any interference.
  arXiv  Detail & Related papers  (2023-01-10T22:05:18Z)
• Full counting statistics as probe of measurement-induced transitions in the quantum Ising chain [62.997667081978825]
  We show that local projective measurements induce a modification of the out-of-equilibrium probability distribution function of the local magnetization. In particular we describe how the probability distribution of the former shows different behaviour in the area-law and volume-law regimes.
  arXiv  Detail & Related papers  (2022-12-19T12:34:37Z)
• Enhanced nonlinear quantum metrology with weakly coupled solitons and particle losses [58.720142291102135]
  We offer an interferometric procedure for phase parameters estimation at the Heisenberg (up to 1/N) and super-Heisenberg scaling levels. The heart of our setup is the novel soliton Josephson Junction (SJJ) system providing the formation of the quantum probe. We illustrate that such states are close to the optimal ones even with moderate losses.
  arXiv  Detail & Related papers  (2021-08-07T09:29:23Z)
• Symmetry enriched phases of quantum circuits [0.0]
  Quantum circuits generate a novel ensemble of quantum many-body states. We classify the phases that can be established as steady states. We discuss close analogies to the theory of spin glasses pioneered by Edwards and Anderson.
  arXiv  Detail & Related papers  (2021-02-18T05:44:22Z)
• Observing a Topological Transition in Weak-Measurement-Induced Geometric Phases [55.41644538483948]
  Weak measurements in particular, through their back-action on the system, may enable various levels of coherent control. We measure the geometric phases induced by sequences of weak measurements and demonstrate a topological transition in the geometric phase controlled by measurement strength. Our results open new horizons for measurement-enabled quantum control of many-body topological states.
  arXiv  Detail & Related papers  (2021-02-10T19:00:00Z)
• Measurement-induced quantum criticality under continuous monitoring [0.0]
  We investigate entanglement phase transitions from volume-law to area-law entanglement in a quantum many-body state under continuous position measurement. We find the signatures of the transitions as peak structures in the mutual information as a function of measurement strength. We propose a possible experimental setup to test the predicted entanglement transition based on the subsystem particle-number fluctuations.
  arXiv  Detail & Related papers  (2020-04-24T19:35:28Z)
• Measurement-induced topological entanglement transitions in symmetric random quantum circuits [0.0]
  We study a class of (1+1)D symmetric random quantum circuits with two competing types of measurements. The circuit exhibits a rich phase diagram involving robust symmetry-protected topological (SPT), trivial, and volume law entangled phases.
  arXiv  Detail & Related papers  (2020-04-15T18:00:00Z)

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.