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arXiv · 1409.1535

Anomalous Weak Values Are Proofs of Contextuality

Matthew F. Pusey
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Abstract

The average result of a weak measurement of some observable $A$ can, under post-selection of the measured quantum system, exceed the largest eigenvalue of $A$. The nature of weak measurements, as well as the presence of post-selection and hence possible contribution of measurement-disturbance, has led to a long-running debate about whether or not this is surprising. Here, it is shown that such "anomalous weak values" are non-classical in a precise sense: a sufficiently weak measurement of one constitutes a proof of contextuality. This clarifies, for example, which features must be present (and in an experiment, verified) to demonstrate an effect with no satisfying classical explanation.

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Matthew F. Pusey. 2014-11-12. Anomalous Weak Values Are Proofs of Contextuality. https://doi.org/10.1103/physrevlett.113.200401

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