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 · Physical Review A · 2018
A method is developed to analyze the performance of sequential measurements, thus providing a way to benchmark various optical receivers. In particular, it is proved that a Dolinar-like receiver cannot realize a ``minimum error quantum measurement'' when dealing with ternary coherent states.