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arXiv:quant-ph/0211122 · Physical Review Letters

Configuration of Separability and Tests for Multipartite Entanglement in Bell-Type Experiments

Koji Nagata, Masato Koashi, Nobuyuki Imoto

Published Dec 10, 2002• 56 citations
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Abstract

We derive tight quadratic inequalities for all kinds of hybrid separable-inseparable n-particle density operators on an arbitrary dimensional space. This methodology enables us to derive a tight quadratic inequality as tests for full n-partite entanglement in various Bell-type correlation experiments on the systems that may not be identified as a collection of qubits, e.g., those involving photons measured by incomplete detectors. It is also proved that when the two measured observables are assumed to precisely anticommute, a stronger quadratic inequality can be used as a witness of full n-partite entanglement.

DOI
10.1103/physrevlett.89.260401

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