Multifractality in monitored single-particle dynamics

• URL: http://arxiv.org/abs/2406.02386v2
• Date: Mon, 17 Jun 2024 08:07:43 GMT
• Title: Multifractality in monitored single-particle dynamics
• Authors: Kohei Yajima, Hisanori Oshima, Ken Mochizuki, Yohei Fuji,
• Abstract summary: We study multifractal properties in time evolution of a single particle subject to repeated measurements. In both cases, multifractal behaviors appear in the ensemble of wave functions or probability distributions conditioned on measurement outcomes.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We study multifractal properties in time evolution of a single particle subject to repeated measurements. For quantum systems, we consider circuit models consisting of local unitary gates and local projective measurements. For classical systems, we consider models for estimating the trajectory of a particle evolved under local transition processes by partially measuring particle occupations. In both cases, multifractal behaviors appear in the ensemble of wave functions or probability distributions conditioned on measurement outcomes after a sufficiently long time. While the nature of particle transport (diffusive or ballistic) qualitatively affects the multifractal properties, they are even quantitatively robust to the measurement rate or specific protocols. On the other hand, multifractality is generically lost by generalized measurements allowing erroneous outcomes or by postselection of the outcomes with no particle detection. We demonstrate these properties by numerical simulations and also propose several simplified models, which allow us to analytically obtain multifractal properties in the monitored single-particle systems.

Related papers

• Theory of free fermions dynamics under partial post-selected monitoring [49.1574468325115]
  We derive a partial post-selected Schrdinger"o equation based on a microscopic description of continuous weak measurement. We show that the passage to the monitored universality occurs abruptly at finite partial post-selection. Our approach establishes a way to study MiPTs for arbitrary subsets of quantum trajectories.
  arXiv  Detail & Related papers  (2023-12-21T16:53:42Z)
• Enhanced Entanglement in the Measurement-Altered Quantum Ising Chain [46.99825956909532]
  Local quantum measurements do not simply disentangle degrees of freedom, but may actually strengthen the entanglement in the system. This paper explores how a finite density of local measurement modifies a given state's entanglement structure.
  arXiv  Detail & Related papers  (2023-10-04T09:51:00Z)
• Deep learning probability flows and entropy production rates in active matter [15.238808518078567]
  We develop a deep learning framework to estimate the score of a high-dimensional probability density. To represent the score, we introduce a novel, spatially-local transformer network architecture. We show that a single network trained on a system of 4096 particles at one packing fraction can generalize to other regions of the phase diagram.
  arXiv  Detail & Related papers  (2023-09-22T16:44:18Z)
• Continuously Monitored Quantum Systems beyond Lindblad Dynamics [68.8204255655161]
  We study the probability distribution of the expectation value of a given observable over the possible quantum trajectories. The measurements are applied to the entire system, having the effect of projecting the system into a product state.
  arXiv  Detail & Related papers  (2023-05-06T18:09:17Z)
• 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)
• Interpretable Joint Event-Particle Reconstruction for Neutrino Physics at NOvA with Sparse CNNs and Transformers [124.29621071934693]
  We present a novel neural network architecture that combines the spatial learning enabled by convolutions with the contextual learning enabled by attention. TransformerCVN simultaneously classifies each event and reconstructs every individual particle's identity. This architecture enables us to perform several interpretability studies which provide insights into the network's predictions.
  arXiv  Detail & Related papers  (2023-03-10T20:36:23Z)
• Dynamic conditioning of two particle discrete-time quantum walks [0.0]
  We study the impact of particle losses in a quantum walk of two photons reconstructing the output probability distributions for one photon conditioned on the loss of the other. We show how localized particle losses change the output distributions without altering their spreading properties. We devise a quantum civilization problem, a two walker generalisation of single particle recurrence processes.
  arXiv  Detail & Related papers  (2023-01-30T10:17:57Z)
• Continuous simultaneous measurement of position and momentum of a particle [0.0]
  We formulate a model of a quantum particle continuously monitored by detectors measuring simultaneously its position and momentum. For sparsely distributed detectors, we use methods from renewal theory of processes to obtain some semi-analytic results. For a semi-continuous spatial distribution of meters the emergence of classical trajectories is shown.
  arXiv  Detail & Related papers  (2022-09-04T12:51:55Z)
• Quantifying multiparticle entanglement with randomized measurements [0.0]
  We exploit the potential of randomized measurements in order to probe the amount of entanglement contained in multiparticle quantum systems. We present a detailed statistical analysis of the underlying measurement resources required for a confident estimation of the introduced quantifiers.
  arXiv  Detail & Related papers  (2022-07-27T20:22:23Z)
• Quench dynamics of R\'enyi negativities and the quasiparticle picture [0.0]
  We study the time evolution after a quantum quench of the moments of the partial transpose. We show that, in the space-time scaling limit of long times and large subsystems, a quasiparticle description allows for a complete understanding of the R'enyi negativities.
  arXiv  Detail & Related papers  (2021-10-27T17:07:25Z)
• Quantum particle across Grushin singularity [77.34726150561087]
  We study the phenomenon of transmission across the singularity that separates the two half-cylinders. All the local realisations of the free (Laplace-Beltrami) quantum Hamiltonian are examined as non-equivalent protocols of transmission/reflection. This allows to comprehend the distinguished status of the so-called bridging' transmission protocol previously identified in the literature.
  arXiv  Detail & Related papers  (2020-11-27T12:53:23Z)

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.