Spin coherence scale: operator-ordering sensitivity beyond Heisenberg-Weyl

• URL: http://arxiv.org/abs/2510.09747v1
• Date: Fri, 10 Oct 2025 18:00:00 GMT
• Title: Spin coherence scale: operator-ordering sensitivity beyond Heisenberg-Weyl
• Authors: Aaron Z. Goldberg, Anaelle Hertz,
• Abstract summary: We introduce the spin coherence scale as a measure of quantum coherence for spin systems.<n>This measure quantifies the off-diagonal coherences of a quantum state in angular momentum bases.<n>It serves as a witness of nonclassicality and provides both upper and lower bounds on the Hilbert-Schmidt distance to the set of classical (spin coherent) states.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: We introduce the spin coherence scale as a measure of quantum coherence for spin systems, generalizing the quadrature coherence scale (QCS) previously defined for quadrature observables. This SU($2$)-invariant measure quantifies the off-diagonal coherences of a quantum state in angular momentum bases, weighted by the classical distinguishability of the superposed states. It serves as a witness of nonclassicality and provides both upper and lower bounds on the Hilbert-Schmidt distance to the set of classical (spin coherent) states. We demonstrate that many hallmark properties of the QCS carry over to the spin setting, including its links to noise susceptibility of a state and moments of quasiprobability distributions. The spin coherence scale has direct implications for quantum metrology in the guise of rotation sensing. We also generalize the framework to SU($n$) systems, identifying the unique SU($n$)-invariant depolarization channel and outlining a broad, Lie-algebraic approach to defining and characterizing the properties of coherence scale beyond harmonic oscillators.

Related papers

• Identifying quantum coherence in quantum annealers [37.067444579637076]
  We use many-body coherent oscillations (MBCO) as a diagnostic for the identification of system-wide coherence in analog quantum simulators.<n>This work gives a general roadmap for the search for quantum coherence in noisy, large-scale quantum platforms.
  arXiv  Detail & Related papers  (2026-02-24T20:39:41Z)
• Freeness Reined in by a Single Qubit [36.94429692322632]
  We find that, even in this setting, the correlation functions predicted by free probability theory receive corrections of order $O(1)$.<n>We trace their origin to non-uniformly distributed stationary quantum states, which we characterize analytically and confirm numerically.
  arXiv  Detail & Related papers  (2025-12-15T19:00:09Z)
• Grassmann Variational Monte Carlo with neural wave functions [45.935798913942904]
  We formalize the framework introduced by Pfau et al.citepfau2024accurate in terms of Grassmann geometry of the Hilbert space.<n>We validate our approach on the Heisenberg quantum spin model on the square lattice, achieving highly accurate energies and physical observables for a large number of excited states.
  arXiv  Detail & Related papers  (2025-07-14T13:53:13Z)
• Theory of the correlated quantum Zeno effect in a monitored qubit dimer [41.94295877935867]
  We show how the competition between two measurement processes give rise to two distinct Quantum Zeno (QZ) regimes.<n>We develop a theory based on a Gutzwiller ansatz for the wavefunction that is able to capture the structure of the Hilbert phase diagram.<n>We show how the two QZ regimes are intimately connected to the topology of the flow of the underlying non-Hermitian Hamiltonian governing the no-click evolution.
  arXiv  Detail & Related papers  (2025-03-28T19:44:48Z)
• Precision bounds for multiple currents in open quantum systems [37.69303106863453]
  We derivation quantum TURs and KURs for multiple observables in open quantum systems undergoing Markovian dynamics.<n>Our bounds are tighter than previously derived quantum TURs and KURs for single observables.<n>We also find an intriguing quantum signature of correlations captured by the off-diagonal element of the Fisher information matrix.
  arXiv  Detail & Related papers  (2024-11-13T23:38:24Z)
• Phase-space gaussian ensemble quantum camouflage [0.0]
  We extend the phase-space description of the Weyl-Wigner quantum mechanics to a subset of non-linear Hamiltonians in position and momentum.<n>For gaussian statistical ensembles, the exact phase-space profile of the quantum fluctuations over the classical trajectories are found.
  arXiv  Detail & Related papers  (2024-09-24T18:14:07Z)
• A New Framework for Quantum Phases in Open Systems: Steady State of Imaginary-Time Lindbladian Evolution [18.47824812164327]
  We introduce the concept of imaginary-time Lindbladian evolution as an alternative framework.<n>This new approach defines gapped quantum phases in open systems through the spectrum properties of the imaginary-Liouville superoperator.<n>Our findings demonstrate universal properties at quantum criticality, such as nonanalytic behaviors of steady-state observables, divergence of correlation lengths, and closing of the imaginary-Liouville gap.
  arXiv  Detail & Related papers  (2024-08-06T14:53:40Z)
• Exploring quantum coherence, spin squeezing and entanglement in an extended spin-1/2 XX Chain [0.0]
  We study the ground state phase diagram of the spin-1/2 XX chain model, which features $XZY-YZX$ type three-spin interactions (TSI) Our research unveils diverse regions within the phase diagram, each characterized by coherent, squeezed, or entangled states.
  arXiv  Detail & Related papers  (2024-01-23T05:51:06Z)
• Quantum circuits to measure scalar spin chirality [0.5134254313682964]
  In quantum information, the scalar spin chirality is a witness of genuine tripartite entanglement. We propose an indirect measurement scheme, based on the Hadamard test, to estimate the scalar spin chirality for general quantum states. We show a single-shot determination of the scalar chirality is possible for chirality eigenstates, via quantum phase estimation with a single auxiliary qutrit.
  arXiv  Detail & Related papers  (2023-06-26T16:05:06Z)
• 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)
• Quantum scars in spin-1/2 isotropic Heisenberg clusters [0.0]
  In the presence of uniform field in one direction, the SU(2) symmetry of the system allows that almost whole spectrum consists of a large number of towers with identical level spacing. Our finding reveals the possibility of quantum information processing that is immune to the thermalization in finite size quantum spin clusters.
  arXiv  Detail & Related papers  (2022-12-23T14:33:41Z)
• Squashed entanglement in one-dimensional quantum matter [0.0]
  We show that edge squashed entanglement discriminates unambiguously between topological insulators and topological superconductors. Such topological squashed entanglement is robust under variations of the sample conditions due to disorder or local perturbations. We show that topological squashed entanglement defines the natural measure of nonlocal correlation patterns in quantum matter.
  arXiv  Detail & Related papers  (2022-07-27T21:40:53Z)
• Rapid thermalization of spin chain commuting Hamiltonians [13.349045680843885]
  We prove that spin chains weakly coupled to a large heat bath thermalize rapidly at any temperature for finite-range, translation-invariant commuting Hamiltonians. This has wide-ranging applications to the study of many-body in and out-of-equilibrium quantum systems.
  arXiv  Detail & Related papers  (2021-12-01T16:08:10Z)

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.