Optimal detection of quantum states via projective measurements

• URL: http://arxiv.org/abs/2509.08556v1
• Date: Wed, 10 Sep 2025 13:03:00 GMT
• Title: Optimal detection of quantum states via projective measurements
• Authors: Giuseppe Del Vecchio Del Vecchio, Satya N. Majumdar,
• Abstract summary: We consider a fully-connected quantum system subjected to random projective measurements.<n>We study the first detection time of an extended subspace of the Hilbert space.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: We consider the quantum dynamical evolution of a fully-connected quantum system subjected to random projective measurements and study the first detection time of an extended subspace of the Hilbert space. Exact analytical expressions are obtained for the mean first detection time and the full first detection probability distribution as functionals of the initial state $\ket{\psi_0}$ and the measurement rate $r$. Exact enumeration agrees perfectly with our analytical predictions.

Related papers

• Measurement-induced crossover in quantum first-detection times [39.98742834565653]
  We show that the measurement back action intrinsic to quantum mechanics may profoundly alter the system dynamics.<n>For a quantum particle in one spatial dimension subject to stroboscopic measurements, we observe an algebraic decay of the probability of the first-detection time if the particle is free.<n>This crossover reflects the purely quantum nature of the detection process, which fundamentally distinguishes it from the first-passage problem in classical systems.
  arXiv  Detail & Related papers  (2026-01-17T16:48:07Z)
• Universal first-passage time statistics for quantum diffusion [0.0]
  We analytically determine the first-passage time distribution, whose form neither depends on the system Hamiltonian nor on the measurement operator.<n>These results provide a general framework to investigate the first-passage statistics of diffusive quantum trajectories.
  arXiv  Detail & Related papers  (2025-11-05T13:21:55Z)
• Quantum Walks: First Hitting Times with Weak Measurements [0.0]
  We study the first detected recurrence time problem of continuous-time quantum walks on graphs.<n>We implement a protocol based on weak measurements on a dilated system, enabling minimally invasive monitoring throughout the evolution.
  arXiv  Detail & Related papers  (2025-06-26T12:01:40Z)
• Fundamental Limits Of Quickest Change-point Detection With Continuous-Variable Quantum States [1.6358505918152435]
  We generalize the quantum CUSUM algorithm for quickest change-point detection to infinite-dimensional quantum systems.<n>We prove that the QUSUM strategy retains its optimality, characterized by the relationship between the expected detection delay and the average false alarm time.
  arXiv  Detail & Related papers  (2025-04-22T20:36:20Z)
• Thermalization and Criticality on an Analog-Digital Quantum Simulator [133.58336306417294]
  We present a quantum simulator comprising 69 superconducting qubits which supports both universal quantum gates and high-fidelity analog evolution. We observe signatures of the classical Kosterlitz-Thouless phase transition, as well as strong deviations from Kibble-Zurek scaling predictions. We digitally prepare the system in pairwise-entangled dimer states and image the transport of energy and vorticity during thermalization.
  arXiv  Detail & Related papers  (2024-05-27T17:40:39Z)
• 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)
• Determination of All Unknown Pure Quantum States with Two Observables [3.19428095493284]
  Efficiently extracting information from pure quantum states using minimal observables on the main system is a longstanding and fundamental issue in quantum information theory. We show that two orthogonal bases are capable of effectively filtering up to $2d-1$ finite candidates by disregarding a measure-zero set. We also show that almost all pure qudits can be uniquely determined by adaptively incorporating a POVM in the middle, followed by measuring the complementary observable.
  arXiv  Detail & Related papers  (2021-08-12T13:46:14Z)
• Bernstein-Greene-Kruskal approach for the quantum Vlasov equation [91.3755431537592]
  The one-dimensional stationary quantum Vlasov equation is analyzed using the energy as one of the dynamical variables. In the semiclassical case where quantum tunneling effects are small, an infinite series solution is developed.
  arXiv  Detail & Related papers  (2021-02-18T20:55:04Z)
• Probing the topological Anderson transition with quantum walks [48.7576911714538]
  We consider one-dimensional quantum walks in optical linear networks with synthetically introduced disorder and tunable system parameters. The option to directly monitor the walker's probability distribution makes this optical platform ideally suited for the experimental observation of the unique signatures of the one-dimensional topological Anderson transition.
  arXiv  Detail & Related papers  (2021-02-01T21:19:15Z)
• Randomly repeated measurements on quantum systems: Correlations and topological invariants of the quantum evolution [0.0]
  We find that the mean number of measurements until the first detection is an integer, namely the dimensionality of the accessible Hilbert space. The main goal of this work is to explain the quantization of the mean return time in terms of a quantized Berry phase.
  arXiv  Detail & Related papers  (2020-12-30T15:05:29Z)
• Quantum probes for universal gravity corrections [62.997667081978825]
  We review the concept of minimum length and show how it induces a perturbative term appearing in the Hamiltonian of any quantum system. We evaluate the Quantum Fisher Information in order to find the ultimate bounds to the precision of any estimation procedure. Our results show that quantum probes are convenient resources, providing potential enhancement in precision.
  arXiv  Detail & Related papers  (2020-02-13T19:35:07Z)

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.