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arXiv · 1706.02125

Optimal discrimination of optical coherent states cannot always be realized by interfering with coherent light, photon counting, and feedback

Kenji Nakahira·Kentaro Kato·Tsuyoshi Sasaki Usuda
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Abstract

It is well known that a minimum error quantum measurement for arbitrary binary optical coherent states can be realized by a receiver that comprises interfering with a coherent reference light, photon counting, and feedback control. We show that, for ternary optical coherent states, a minimum error measurement cannot always be realized by such a receiver. The problem of finding an upper bound on the maximum success probability of such a receiver can be formulated as a convex programming. We derive its dual problem and numerically find the upper bound. At least for ternary phase-shift keyed coherent states, this bound does not reach that of a minimum error measurement.

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Kenji Nakahira, Kentaro Kato, Tsuyoshi Sasaki Usuda. 2017-06-07. Optimal discrimination of optical coherent states cannot always be realized by interfering with coherent light, photon counting, and feedback. https://doi.org/10.1103/physreva.97.022320

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