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Bell's theorem without inequalities and without alignments

Adan Cabello
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Abstract

A proof of Bell's theorem without inequalities is presented which exhibits three remarkable properties: (a) reduced local states are immune to collective decoherence; (b) distant local setups do not need to be aligned, since the required perfect correlations are achieved for any local rotation of the local setups; (c) local measurements require only individual measurements on the qubits. Indeed, it is shown that this proof is essentially the only one which fulfils (a), (b), and (c).

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Adan Cabello. 2004-02-12. Bell's theorem without inequalities and without alignments. https://doi.org/10.1103/physrevlett.91.230403

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