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Witnessing effective entanglement in a continuous variable prepare&measure setup and application to a QKD scheme using postselection

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 نشر من قبل Stefan Lorenz
 تاريخ النشر 2006
  مجال البحث فيزياء
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We report an experimental demonstration of effective entanglement in a prepare&measure type of quantum key distribution protocol. Coherent polarization states and heterodyne measurement to characterize the transmitted quantum states are used, thus enabling us to reconstruct directly their Q-function. By evaluating the excess noise of the states, we experimentally demonstrate that they fulfill a non-separability criterion previously presented by Rigas et al. [J. Rigas, O. Guhne, N. Lutkenhaus, Phys. Rev. A 73, 012341 (2006)]. For a restricted eavesdropping scenario we predict key rates using postselection of the heterodyne measurement results.



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