Operational detection of Wigner negativity in arbitrary quantum states from few copies

• URL: http://arxiv.org/abs/2606.26084v1
• Date: Wed, 24 Jun 2026 17:55:58 GMT
• Title: Operational detection of Wigner negativity in arbitrary quantum states from few copies
• Abstract summary: We develop a framework to detect Wigner negativity of arbitrary states using experimentally observable moments of Wigner function.<n>We show that our framework extends naturally to identifying nonclassical resources in continuous-variable systems.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: States with negative Wigner functions form a fundamental class of nonclassical resource underlying quantum advantage. Here we develop a unified framework to detect Wigner negativity of arbitrary states using experimentally accessible moments of the Wigner function that can be estimated from a modest number of state copies. Exploiting constraints satisfied by positive phase-space distributions, we derive complementary hierarchies of negativity criteria based on $\mathcal{L}_p$-norm inequalities, log-convexity relations, and Hankel-matrix positivity, yielding increasingly powerful witnesses of Wigner negativity without full phase-space tomography. The framework further enables quantitative characterization of Wigner negativity from a small number of experimentally accessible observables. Next, we establish an exact multicopy representation of all Wigner moments as expectation values of parity-based observables, providing a practical and scalable route to their experimental estimation. We demonstrate the performance of our scheme through numerical simulations of randomized-measurement and classical-shadow protocols. Finally, we show that the framework extends naturally to identifying nonclassical resources such as bipartite and multipartite entanglement. These results establish Wigner moments as a versatile tool for the scalable detection and quantification of nonclassical resources in continuous-variable quantum systems.

Related papers

• Quantifying Margenau--Hill Nonclassicality [0.0]
  We introduce the logarithmic MHQ negativity as a quantifier of nonclassicality, and then derive a hierarchy of rigorous lower bounds in terms of low-order moments.<n>For qubits, we further derive a tight upper bound on the exact MHQ negativity and identify the corresponding extremal state.<n>Our results establish a moment-based framework for extracting quantitative information about MHQ negativity from a finite set of low-order observables.
  arXiv  Detail & Related papers  (2026-09-07T18:30:25Z)
• First appearance of quasiprobability negativity in quantum many-body dynamics [0.0]
  We introduce the emphfirst-time negativity (FTN) of the Margenau-Hill quasiprobability as a dynamical indicator of when local measurement sequences in an interacting quantum system begin to exhibit genuinely nonclassical behavior.<n>FTN discriminates clearly between interaction-dominated and field-dominated regimes, is systematically reshaped by temperature, and responds to sensitively breaking.<n>Our results identify FTN as a practical and experimentally probebility of real-time quantum coherence and contextuality, directly suited to current platforms capable of sequential weak and strong measurements.
  arXiv  Detail & Related papers  (2026-01-01T08:25:27Z)
• Unregularized Linear Convergence in Zero-Sum Game from Preference Feedback [50.89125374999765]
  We provide the first convergence guarantee for Optimistic Multiplicative Weights Update ($mathtOMWU$) in NLHF.<n>Our analysis identifies a novel marginal convergence behavior, where the probability of rarely played actions grows exponentially from exponentially small values.
  arXiv  Detail & Related papers  (2025-12-31T12:08:29Z)
• Wigner function negativity in a classical model of quantum light [0.0]
  We show a classical model of squeezed light that is capable of reproducing observed behavior of single-photon added coherent states.<n>The resulting Wigner functions exhibit negatively for photon-added vacuum and weak coherent states.
  arXiv  Detail & Related papers  (2025-12-15T16:00:04Z)
• Efficient detection of nonclassicality using moments of the Wigner function [0.0]
  We provide a criterion for detecting quantum states characterized by a negative Wigner function.<n>Our method relies on evaluating moments of the Wigner function, which involves computing simple functionals.<n>We propose an experimental method utilizing the mode SWAP operator to realize these moments in a real experiment.
  arXiv  Detail & Related papers  (2024-07-16T18:54:41Z)
• Generalization Metrics for Practical Quantum Advantage in Generative Models [68.8204255655161]
  Generative modeling is a widely accepted natural use case for quantum computers. We construct a simple and unambiguous approach to probe practical quantum advantage for generative modeling by measuring the algorithm's generalization performance. Our simulation results show that our quantum-inspired models have up to a $68 times$ enhancement in generating unseen unique and valid samples.
  arXiv  Detail & Related papers  (2022-01-21T16:35:35Z)
• Deconfounding Scores: Feature Representations for Causal Effect Estimation with Weak Overlap [140.98628848491146]
  We introduce deconfounding scores, which induce better overlap without biasing the target of estimation. We show that deconfounding scores satisfy a zero-covariance condition that is identifiable in observed data. In particular, we show that this technique could be an attractive alternative to standard regularizations.
  arXiv  Detail & Related papers  (2021-04-12T18:50:11Z)
• Quantification of Wigner Negativity Remotely Generated via Einstein-Podolsky-Rosen Steering [11.427047150248708]
  Wigner negativity plays an essential role in quantum computing and simulation using continuous-variable systems. Motivated by the demand of real-world quantum network, here we investigate the shareability of generated Wigner negativity in the multipartite scenario. Our results pave the way for exploiting Wigner negativity as a valuable resource for numerous quantum information protocols based on non-Gaussian scenario.
  arXiv  Detail & Related papers  (2021-04-01T13:07:54Z)
• Witnessing Wigner Negativity [0.0]
  Negativity of the Wigner function is arguably one of the most striking non-classical features of quantum states. We derive witnesses for Wigner negativity of quantum states based on fidelities with Fock states. We show that our witnesses form a complete family - each Wigner negative state is detected by at least one witness.
  arXiv  Detail & Related papers  (2021-02-11T18:55:44Z)
• Nonparametric Score Estimators [49.42469547970041]
  Estimating the score from a set of samples generated by an unknown distribution is a fundamental task in inference and learning of probabilistic models. We provide a unifying view of these estimators under the framework of regularized nonparametric regression. We propose score estimators based on iterative regularization that enjoy computational benefits from curl-free kernels and fast convergence.
  arXiv  Detail & Related papers  (2020-05-20T15:01:03Z)
• Understanding Negative Sampling in Graph Representation Learning [87.35038268508414]
  We show that negative sampling is as important as positive sampling in determining the optimization objective and the resulted variance. We propose Metropolis-Hastings (MCNS) to approximate the positive distribution with self-contrast approximation and accelerate negative sampling by Metropolis-Hastings. We evaluate our method on 5 datasets that cover extensive downstream graph learning tasks, including link prediction, node classification and personalized recommendation.
  arXiv  Detail & Related papers  (2020-05-20T06:25:21Z)
• Learning from Aggregate Observations [82.44304647051243]
  We study the problem of learning from aggregate observations where supervision signals are given to sets of instances. We present a general probabilistic framework that accommodates a variety of aggregate observations. Simple maximum likelihood solutions can be applied to various differentiable models.
  arXiv  Detail & Related papers  (2020-04-14T06:18:50Z)

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.