English

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

Quantum Physics 2018-02-16 v2

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.

Keywords

Cite

@article{arxiv.1706.02125,
  title  = {Optimal discrimination of optical coherent states cannot always be realized by interfering with coherent light, photon counting, and feedback},
  author = {Kenji Nakahira and Kentaro Kato and Tsuyoshi Sasaki Usuda},
  journal= {arXiv preprint arXiv:1706.02125},
  year   = {2018}
}