标题： 片上错误计数用于混合金属单电子闸门 显示英文标题

标题： On-chip error counting for hybrid metallic single-electron turnstiles

摘要： 我们对基于超小正常金属-绝缘体-超导体隧道结的单电子翻转器中通过的单个电子进行了原位检测。 在我们的设置中，由于检测器带宽的限制，在低重复率下，我们观察到系统中无错误的逐个传输多达几百个电子。 在高达100 kHz的泵浦速度下，我们展示了相对误差率低至10^-3，与非优化单个翻转器平均泵浦电流测量得到的典型值相当。 这项工作是实现基于金属单电子翻转器的自参考电流标准的初步步骤，补充了基于半导体量子点泵浦的方法。 这是首次在操作频率超过检测器带宽的情况下，在可以同时测量平均泵浦电流的配置中实现了片上泵浦误差检测。 在该方案中，电子是从翻转器的超导电极进行计数的，而不是直接探测正常金属岛，这使得能够研究混合结构中的基本高阶隧穿过程，这些过程以前在更简单的配置中无法触及。 显示英文摘要

摘要： We perform in-situ detection of individual electrons pumped through a single-electron turnstile based on ultrasmall normal metal - insulator - superconductor tunnel junctions. In our setup, limited by the detector bandwidth, at low repetition rates we observe errorless sequential transfer of up to several hundred electrons through the system. At faster pumping speeds up to 100 kHz, we show relative error rates down to 10^-3, comparable to typical values obtained from measurements of average pumped current in non-optimized individual turnstiles. The work constitutes an initial step towards a self-referenced current standard realized with metallic single-electron turnstiles, complementing approaches based on semiconductor quantum dot pumps. It is the first demonstration of on-chip pumping error detection at operation frequencies exceeding the detector bandwidth, in a configuration where the average pumped current can be simultaneously measured. The scheme in which electrons are counted from the superconducting lead of the turnstile, instead of direct probing of the normal metal island, also enables studies of fundamental higher-order tunneling processes in the hybrid structures, previously not in reach with simpler configurations.