Charge and Spin Sharpening Transitions on Dynamical Quantum Trees

• URL: http://arxiv.org/abs/2405.13894v1
• Date: Wed, 22 May 2024 18:06:15 GMT
• Title: Charge and Spin Sharpening Transitions on Dynamical Quantum Trees
• Authors: Xiaozhou Feng, Nadezhda Fishchenko, Sarang Gopalakrishnan, Matteo Ippoliti,
• Abstract summary: 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.
• Score: 0.027042267806481293
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: The dynamics of monitored systems can exhibit a measurement-induced phase transition (MIPT) between entangling and disentangling phases, tuned by the measurement rate. When the dynamics obeys a continuous symmetry, the entangling phase further splits into a fuzzy phase and a sharp phase based on the scaling of fluctuations of the symmetry charge. While the sharpening transition for Abelian symmetries is well understood analytically, no such understanding exists for the non- Abelian case. In this work, building on a recent analytical solution of the MIPT on tree-like circuit architectures (where qubits are repatedly added or removed from the system in a recursive pattern), we study entanglement and sharpening transitions in monitored dynamical quantum trees obeying U (1) and SU (2) symmetries. The recursive structure of tree tensor networks enables powerful analytical and numerical methods to determine the phase diagrams in both cases. In the U (1) case, we analytically derive a Fisher-KPP-like differential equation that allows us to locate the critical point and identify its properties. 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. In this limit, we analytically solve the boundaries separating the fuzzy and sharp phases, and find them to be in agreement with exact numerical simulations.

Related papers

• Probing quantum floating phases in Rydberg atom arrays [61.242961328078245]
  We experimentally observe the emergence of the quantum floating phase in 92 neutral-atom qubits. The site-resolved measurement reveals the formation of domain walls within the commensurate ordered phase. As the experimental system sizes increase, we show that the wave vectors approach a continuum of values incommensurate with the lattice.
  arXiv  Detail & Related papers  (2024-01-16T03:26:36Z)
• Action formalism for geometric phases from self-closing quantum trajectories [55.2480439325792]
  We study the geometric phase of a subset of self-closing trajectories induced by a continuous Gaussian measurement of a single qubit system. We show that the geometric phase of the most likely trajectories undergoes a topological transition for self-closing trajectories as a function of the measurement strength parameter.
  arXiv  Detail & Related papers  (2023-12-22T15:20:02Z)
• Critical phase and spin sharpening in SU(2)-symmetric monitored quantum circuits [1.188383832081829]
  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"
  arXiv  Detail & Related papers  (2023-05-22T18:00:01Z)
• 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)
• Measurement-induced phase transitions on dynamical quantum trees [0.0]
  We show a transition at a nontrivial value of the measurement strength, with the real measurement case exhibiting a smaller entangling phase. An intriguing difference between the two cases is that the real measurement case lies at the boundary between two distinct types of critical scaling. We propose a protocol for realizing a measurement phase transition experimentally via an expansion process.
  arXiv  Detail & Related papers  (2022-10-13T18:00:54Z)
• Emergent XY* transition driven by symmetry fractionalization and anyon condensation [0.0]
  We study the phase diagram and anyon condensation transitions of a $mathbbZ$ topological order perturbed by Ising interactions in the Toric Code. The interplay between the global Ising symmetry and the lattice space group symmetries results in a non-trivial symmetry fractionalization class for the anyons. We provide numerical evidence for the occurrence of two symmetry breaking patterns predicted by the specific symmetry fractionalization class of the anyons in the explored phase diagram.
  arXiv  Detail & Related papers  (2022-04-07T18:00:00Z)
• Phase diagram of Rydberg-dressed atoms on two-leg square ladders: Coupling supersymmetric conformal field theories on the lattice [52.77024349608834]
  We investigate the phase diagram of hard-core bosons in two-leg ladders in the presence of soft-shoulder potentials. We show how the competition between local and non-local terms gives rise to a phase diagram with liquid phases with dominant cluster, spin, and density-wave quasi-long-range ordering.
  arXiv  Detail & Related papers  (2021-12-20T09:46:08Z)
• 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.