We report on measurements of the switching current distributions on two-dimensional NbN superconducting nanostrip single-photon detectors (SNSPD), 5 nm thick and 80 nm wide, in an interval of temperatures from 6 K down to 0.3 K and compare the data with those obtained for similar NbTiN nanostrips. The standard deviations of the switching distributions show an extended region at high temperatures where multiple phase slip switching events occur. This is probably related to a decreasing critical current and an increasing electron and phonon heat capacities. In this temperature region, the width of the switching distribution, and therefore the dark count rate, is considerably reduced down to values below those observed at the lowest temperature. Finally, we also quantify the energy scale of the fluctuation phenomena. The proposed experimental approach may result in a powerful tool for the diagnostic of SNSPD operation mode.

中文翻译：

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多次波动事件在 NbN 和 NbTiN 超导纳米带单光子探测器中的作用

我们报告了在 5 nm 厚和 80 nm 宽的二维 NbN 超导纳米带单光子探测器 (SNSPD) 上的开关电流分布测量结果，温度区间为 6 K 至 0.3 K，并将数据与这些数据进行比较获得了类似的 NbTiN 纳米带。开关分布的标准偏差显示了高温下发生多相滑动开关事件的扩展区域。这可能与降低的临界电流和增加的电子和声子热容有关。在该温度范围内，开关分布的宽度以及暗计数率显着降低至低于在最低温度下观察到的值。最后，我们还量化了波动现象的能量尺度。