Separability of quantum states and the violation of Bell-type inequalities
- Department of Mathematical Sciences, University of Aarhus, Ny Munkegade, DK-8000, Aarhus C (Denmark)
In contrast to the widespread opinion that any separable quantum state satisfies every classical probabilistic constraint, we present a simple example where separable quantum state does not satisfy the original Bell inequality although the latter inequality, in its perfect correlation form, is valid for all joint classical measurements. In a very general setting, we discuss inequalities for joint experiments upon a bipartite quantum system. For any separable quantum state, we derive quantum analogs of the original Bell inequality and specify the conditions sufficient for a separable state to satisfy the original Bell inequality. We introduce the extended Clauser-Horne-Shimony-Holt inequality and prove that, for any separable quantum state, this inequality holds for a variety of linear combinations.
- OSTI ID:
- 20640937
- Journal Information:
- Physical Review. A, Journal Name: Physical Review. A Journal Issue: 4 Vol. 69; ISSN 1050-2947; ISSN PLRAAN
- Country of Publication:
- United States
- Language:
- English
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