Large speed-up of quantum emitter detection via quantum interference

Quantum emitters are a key resource in quantum technologies, microscopy, and other applications. The ability to rapidly detect them is useful both for quality control in engineered emitter arrays and for high-contrast imaging of naturally occurring emitters. Using full photon-counting statistics and optimal Bayesian hypothesis testing, we show that extended Hong-Ou-Mandel interference between quantum emission and a coherent field enables orders-of-magnitude speed-ups in emitter detection under realistic noise and loss. Strikingly, the performance advantage improves as loss and background noise increase, and persists for incoherent emission. Taken together with prior demonstrations of extended Hong-Ou-Mandel interference, this suggest that substantial performance gains are achievable with current technology under realistic, non-ideal conditions. This offers a new approach to fast, low-intensity imaging and for emitter characterization in large-scale quantum systems. Fundamentally, the discovery that quantum interference and measurements, used together, are more robust to both loss and noise than standard measurement techniques opens the possibility of broad applications across quantum metrology.