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arXiv · 1509.08438

Remote preparation of $W$ states from imperfect bipartite sources

M. G. M. Moreno·Márcio M. Cunha·Fernando Parisio
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Abstract

Several proposals to produce {\it tripartite} $W$-type entanglement are probabilistic even if no imperfections are considered in the processes. We provide a deterministic way to remotely create $W$ states out of an EPR source. The proposal is made viable through measurements (which can be demolitive) in an appropriate three-qubit basis. The protocol becomes probabilistic only when source flaws are considered. It turns out that, even in this situation, it is robust against imperfections in two senses: (i) It is possible, after postselection, to create a pure ensemble of $W$ states out of an EPR source containing a systematic error; (ii) If no postselection is done, the resulting mixed state has a fidelity, with respect to a pure $|W\rangle$, which is higher than that of the imperfect source in comparison to an ideal EPR source. This simultaneously amounts to entanglement concentration and {\it lifting}.

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M. G. M. Moreno, Márcio M. Cunha, Fernando Parisio. 2016-08-25. Remote preparation of $W$ states from imperfect bipartite sources. https://doi.org/10.1007/s11128-016-1358-0

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