Weak-measurement-induced phases and dephasing: broken symmetry of the geometric phase

• URL: http://arxiv.org/abs/2006.14641v3
• Date: Wed, 20 Oct 2021 18:03:52 GMT
• Title: Weak-measurement-induced phases and dephasing: broken symmetry of the geometric phase
• Authors: Kyrylo Snizhko, Nihal Rao, Parveen Kumar, and Yuval Gefen
• Abstract summary: Coherent steering of a quantum state, induced by a sequence of weak measurements, has become an active area of theoretical and experimental study. Superseding common wisdom, we show that the symmetric and the antisymmetric components do not correspond to the dynamical and geometrical parts respectively. We find transitions between different topologically distinct sectors, defined by integer-valued winding numbers, and show that the transitions are accompanied by diverging dephasing.
• Score: 1.4174475093445233
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Coherent steering of a quantum state, induced by a sequence of weak measurements, has become an active area of theoretical and experimental study. For a closed steered trajectory, the underlying phase factors involve both geometrical and dynamical terms. Furthermore, considering the reversal of the order of the measurement sequence, such a phase comprises a symmetric and an antisymmetric term. Superseding common wisdom, we show that the symmetric and the antisymmetric components do not correspond to the dynamical and geometrical parts respectively. Addressing a broad class of measurement protocols, we further investigate the dependence of the induced phases on the measurement parameters (e.g., the measurement strength). We find transitions between different topologically distinct sectors, defined by integer-valued winding numbers, and show that the transitions are accompanied by diverging dephasing. We propose experimental protocols to observe these effects.

Related papers

• Constants of motion characterizing continuous symmetry-broken phases [0.0]
  We present a theory characterizing the phases emerging as a consequence of continuous symmetry-breaking in quantum and classical systems. Our theory is numerically exemplified via the two-dimensional limit of the vibron model.
  arXiv  Detail & Related papers  (2024-02-14T15:36:29Z)
• 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)
• Phases of Matrix Product States with Symmetric Quantum Circuits and Symmetric Measurements with Feedforward [0.2010986461330016]
  Two matrix product states (MPS) are in the same phase in the presence of symmetries. We consider how symmetry-preserving measurements with feedforward alter the phase classification of MPS in the presence of global on-site symmetries.
  arXiv  Detail & Related papers  (2023-12-21T13:38:46Z)
• Measuring Topological Field Theories: Lattice Models and Field-Theoretic Description [2.541410020898643]
  Recent years have witnessed a surge of interest in performing measurements within topological phases of matter. We present a field-theoretic framework for describing measurements within topological field theories.
  arXiv  Detail & Related papers  (2023-10-26T19:26:04Z)
• 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)
• 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)
• Topological transitions of the generalized Pancharatnam-Berry phase [55.41644538483948]
  We show that geometric phases can be induced by a sequence of generalized measurements implemented on a single qubit. We demonstrate and study this transition experimentally employing an optical platform. Our protocol can be interpreted in terms of environment-induced geometric phases.
  arXiv  Detail & Related papers  (2022-11-15T21:31:29Z)
• Generalized quantum measurements with matrix product states: Entanglement phase transition and clusterization [58.720142291102135]
  We propose a method for studying the time evolution of many-body quantum lattice systems under continuous and site-resolved measurement. We observe a peculiar phenomenon of measurement-induced particle clusterization that takes place only for frequent moderately strong measurements, but not for strong infrequent measurements.
  arXiv  Detail & Related papers  (2021-04-21T10:36:57Z)
• 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)
• Weak-measurement-induced asymmetric dephasing: manifestation of intrinsic measurement chirality [1.4174475093445233]
  We study sequences of generalized (weak) measurements that steer a system in a closed trajectory. The readout process is marked by fluctuations, giving rise to dephasing. The dephasing diverges at certain protocol parameters, marking topological transitions in the measurement-induced phase factor.
  arXiv  Detail & Related papers  (2020-06-23T18:01:21Z)

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.