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Nonlinear Improvement of Qubit-qudit Entanglement Witnesses

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 نشر من قبل Shu-Qian Shen
 تاريخ النشر 2020
  مجال البحث فيزياء
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The entanglement witness is an important and experimentally applicable tool for entanglement detection. In this paper, we provide a nonlinear improvement of any entanglement witness for $2otimes d$ quantum systems. Compared with any existing entanglement witness, the improved separability criterion only needs two more measurements on local observables. Detailed examples are employed to illustrate the efficiency of the nonlinear improvement for general, optimal and non-decomposable entanglement witnesses.



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