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  • Open Access

Verification of contextuality by noncontextual experiments

Jonathan J. Thio1, Wilfred Salmon2,3, Crispin H. W. Barnes1, Stephan De Bièvre4, and David R. M. Arvidsson-Shukur3

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Phys. Rev. A 112, 062230 – Published 19 December, 2025

DOI: https://doi.org/10.1103/mzw5-t326

Abstract

We uncover features of generalized contextuality by connecting it to the Kirkwood-Dirac (KD) quasiprobability distribution. Quantum states can be represented by KD distributions, which take values in the complex unit disk. Only for “KD-positive” states are the KD distributions joint probability distributions. A KD distribution can be measured by a series of weak and projective measurements. We design such an experiment and show that it is contextual iff the underlying state is not KD positive. We analyze this connection with respect to mixed KD-positive states that cannot be decomposed as convex combinations of pure KD-positive states. Our result is the construction of a noncontextual experiment that enables an experimenter to verify contextuality.

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Phys. Rev. A 112, 062230– Published 19 December, 2025
  • Received 17 January 2025
  • Accepted 17 November 2025
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