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Counterfactual entanglement and nonlocal correlations in separable states

Oliver Cohen
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Abstract

It is shown that the outcomes of measurements on systems in separable mixed states can be partitioned, via subsequent measurements on a disentangled extraneous system, into subensembles that display the statistics of entangled states. This motivates the introduction of the concept of "counterfactual" entanglement, which can be associated with all separable mixed states including those that are factorable. This type of entanglement gives rise to a new kind of postselection-induced Bell inequality violation. The significance of counterfactual entanglement, and its physical implications, are assessed.

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Oliver Cohen. 1999-07-30. Counterfactual entanglement and nonlocal correlations in separable states. https://doi.org/10.1103/physreva.60.80

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