We propose an efficient decomposition scheme for a quantum receiver that attains the Helstrom bound in the low-photon regime for discriminating binary coherent states. Our method, which avoids feedback as used in Dolinar's case, breaks down nonlinear operations into basic gates used in continuous-variable quantum computation. We account for realistic conditions by examining the impact of photon loss and imperfect photon detection, including the presence of dark counts, while presenting squeezing as a technique to mitigate these noise sources and maintain the advantage over SQL. Our scheme motivates testing quantum advantages with cubic-phase gates and designing photonic quantum computers to optimize symbol-by-symbol measurements in optical communication.
@article{arxiv.2410.21800,
title = {Photonic Quantum Receiver Attaining the Helstrom Bound},
author = {Aakash Warke and Janis Nötzel and Kan Takase and Warit Asavanant and Hironari Nagayoshi and Kosuke Fukui and Shuntaro Takeda and Akira Furusawa and Peter van Loock},
journal= {arXiv preprint arXiv:2410.21800},
year = {2024}
}