We have been developing readout interfaces for superconducting nanowire single-photon detectors (SSPDs) using adiabatic quantum-flux-parametron (AQFP) logic. AQFP circuits operate with low power consumption, low bias currents, and high sensitivity, and thus are suitable as readout interfaces for large SSPD arrays. In this study, we develop a high-sensitivity AQFP interface, consisting of a current transformer, comparator, and rising-edge detector. We systematically investigated the current sensitivity of the AQFP interface by operating an NbTiN SSPD with the interface in a 0.1 W Gifford–McMahon cryocooler. We compared the outputs from the AQFP interface with the direct outputs from the SSPD, thereby demonstrating a sensitivity of 3.5 μA, which is much smaller than that of the single-flux-quantum interfaces that we developed before.

我们已经开发了使用绝热量子通量参量分子（AQFP）逻辑的超导纳米线单光子探测器（SSPD）的读出接口。AQFP电路以低功耗，低偏置电流和高灵敏度工作，因此适合用作大型SSPD阵列的读出接口。在这项研究中，我们开发了一个高灵敏度的AQFP接口，该接口由电流互感器，比较器和上升沿检测器组成。我们通过在0.1 W Gifford-McMahon低温冷却器中对NbTiN SSPD进行操作，系统地研究了AQFP接口的当前灵敏度。我们比较来自AQFP接口与来自SSPD直接输出的输出，从而表明3.5的灵敏度μA，它比我们之前开发的单磁通量子接口小得多。