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Symmetric extensions of quantum States and local hidden variable theories
Barbara M Terhal1, Andrew C Doherty, David Schwab
1IBM Watson Research Center, P.O. Box 218, Yorktown Heights, NY 10598, USA.
Abstract:
While all bipartite pure entangled states violate some Bell inequality, the relationship between entanglement and nonlocality for mixed quantum states is not well understood. We introduce a simple and efficient algorithmic approach for the problem of constructing local hidden variable theories for quantum states. The method is based on constructing a so-called symmetric quasiextension of the quantum state that gives rise to a local hidden variable model with a certain number of settings for the observers Alice and Bob.
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