Single-Shot Fidelity Reveals Hard and Soft Limits: A Universal Yardstick for Photon-Number-Resolving Detectors

Tetsuya Tsuruta, Akio Yoshizawa, Daiji Fukuda

Photon-number-resolving (PNR) detectors are essential for photonic quantum computing, where a single measurement outcome must reliably herald a specific quantum state. However, det…