Contextuality Can be Verified with Noncontextual Experiments

• URL: http://arxiv.org/abs/2412.00199v1
• Date: Fri, 29 Nov 2024 19:01:03 GMT
• Title: Contextuality Can be Verified with Noncontextual Experiments
• Authors: Jonathan J. Thio, Wilfred Salmon, Crispin H. W. Barnes, Stephan De Bièvre, David R. M. Arvidsson-Shukur,
• Abstract summary: Quantum states can be represented by KD distributions, which take values in the complex unit disc. A KD distribution can be measured by a series of weak and projective measurements. We analyze this connection with respect to mixed KD-positive states that cannot be decomposed as convex combinations of pure KD-positive states.
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• Abstract: We uncover new 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 disc. 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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