Ultrafast low-jitter optical response in high-temperature superconducting microwires

We report ultrafast optical response in high-T_c superconductor ( YB a 2 C u 3 O 7 − δ ) based microwires operating at 76 K and we find a rise time ∼850 ps and a fall time ∼1250 ps and an upper limit of timing jitter of ∼100 ps, using twice the standard deviation of the fitted data. In our experiment, incident power is proven to be an important factor for a device jitter. At low incident power, a lower rate of hot-spot generation by a smaller number of absorbed photons results in a longer latency time to obtain the required number of hot-spots for superconductor-to-normal transition. The lower hot-spot generation rate also results in larger timing jitter of the device. Whereas, at high incident power, a higher hot-spot generation rate yields shorter latency and smaller timing jitter. These observations agree well with our statistical model. Enhancing the sensitivity of the current device can enable future high-T_c superconductor nanowire single photon detectors, toward the widespread use of ultrafast quantum technologies.