Better photon timing could speed up quantum information processing

Superconducting nanowire single-photon detectors have now achieved timing jitter in the few-picosecond regime, marking them as among the most precise photon-timing technologies available. However, maintaining this precision becomes a central challenge at count rates exceeding tens of Mcps and above. Experimental observations reveal substantial timing broadening persists even when expected deterministic effects are suppressed, suggesting an additional physical mechanism is at play. This indicates that, under high-count-rate operation, baseline fluctuations directly convert into timing uncertainty, potentially limiting performance in applications like quantum information processing. Achieving few-picosecond timing resolution is now commonplace with superconducting nanowire single-photon detectors, positioning them as leading technologies for precise photon arrival time measurement. Existing explanations for timing jitter at these rates often focus on deterministic effects like multiphoton responses and pulse pile-up, but recent work reveals a more subtle mechanism. Experiments demonstrate…