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Nonsequential positive-operator-valued measurements on entangled mixed states do not always violate a Bell inequality

Jonathan Barrett
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Abstract

We present a local-hidden-variable model for positive-operator-valued measurements (an LHVPOV model) on a class of entangled generalized Werner states, thus demonstrating that such measurements do not always violate a Bell-type inequality. We also show that, in general, if the state $ρ'$ can be obtained from $ρ$ with certainty by local quantum operations without classical communication then an LHVPOV model for the state $ρ$ implies the existence of such a model for $ρ'$.

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Jonathan Barrett. 2002-04-15. Nonsequential positive-operator-valued measurements on entangled mixed states do not always violate a Bell inequality. https://doi.org/10.1103/physreva.65.042302

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