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arXiv · 0912.2610

Unitary-process discrimination with error margin

T. Hashimoto·A. Hayashi·M. Hayashi·M. Horibe
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Abstract

We investigate a discrimination scheme between unitary processes. By introducing a margin for the probability of erroneous guess, this scheme interpolates the two standard discrimination schemes: minimum-error and unambiguous discrimination. We present solutions for two cases. One is the case of two unitary processes with general prior probabilities. The other is the case with a group symmetry: the processes comprise a projective representation of a finite group. In the latter case, we found that unambiguous discrimination is a kind of "all or nothing": the maximum success probability is either 0 or 1. We also closely analyze how entanglement with an auxiliary system improves discrimination performance.

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T. Hashimoto, A. Hayashi, M. Hayashi, M. Horibe. 2010-06-10. Unitary-process discrimination with error margin. https://doi.org/10.1103/physreva.81.062327

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