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arXiv · 0712.1616

Unambiguous comparison of ensembles of quantum states

Michal Sedlak·Mario Ziman·Vladimir Buzek·Mark Hillery
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Abstract

We present a solution of the problem of the optimal unambiguous comparison of two ensembles of unknown quantum states (psi_1)^k and (psi_2)^l. We consider two cases: 1) The two unknown states psi_1 and psi_2 are arbitrary states of qudits. 2) Alternatively, they are coherent states of a harmonic oscillator. For the case of coherent states we propose a simple experimental realization of the optimal "comparison" machine composed of a finite number of beam-splitters and a single photodetector.

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Michal Sedlak, Mario Ziman, Vladimir Buzek, Mark Hillery. 2007-12-11. Unambiguous comparison of ensembles of quantum states. https://doi.org/10.1103/physreva.77.042304

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