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Characterization of multiqubit pure-state entanglement

Zeqian Chen·Quanhua Xu
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Abstract

A necessary and sufficient entanglement criterion based on variances of Mermin-Klyshko's Bell operators is proved for multiqubit pure states. Contrary to Bell's inequalities, entangled pure states strictly satisfy a quadratic inequality but product ones can attain the equality under some local unitary transformations, which can be obtained by solving a quadratic maximum problem. This presents a characterization of multiqubit pure-state entanglement.

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Zeqian Chen, Quanhua Xu. 2005-05-23. Characterization of multiqubit pure-state entanglement. https://doi.org/10.1103/physreva.73.034306

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