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arXiv · 1606.02215

Entanglement without hidden nonlocality

Flavien Hirsch·Marco Túlio Quintino·Joseph Bowles·Tamás Vértesi·Nicolas Brunner
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Abstract

We consider Bell tests in which the distant observers can perform local filtering before testing a Bell inequality. Notably, in this setup, certain entangled states admitting a local hidden variable model in the standard Bell scenario can nevertheless violate a Bell inequality after filtering, displaying so-called hidden nonlocality. Here we ask whether all entangled states can violate a Bell inequality after well-chosen local filtering. We answer this question in the negative by showing that there exist entangled states without hidden nonlocality. Specifically, we prove that some two-qubit Werner states still admit a local hidden variable model after any possible local filtering on a single copy of the state.

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Flavien Hirsch, Marco Túlio Quintino, Joseph Bowles, Tamás Vértesi, Nicolas Brunner. 2016-06-07. Entanglement without hidden nonlocality. https://doi.org/10.1088/1367-2630/18/11/113019

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