本工作提出了一种通过对时间的测量来获得单个Josephson结的跳变电流统计分布P(I)的电路,该电路具有很好的精度和速度.利用该电路我们首次从4.2K到30mK的不同温度下,对NbN/AIN/AbN结和Nb/A10x/Nb结的跳变电流统计分布进行了测量,得到了一系列P(I).在一定的温度范围内,P(I)和理论值符合的很好.该电路结合其他的实验手段,将在今后研究Josephson结其他物理性质(例如Rabi振荡)中发挥很好的作用。
We have presented a scheme using the time domain method to measure the distribution of a Josephson junction's switching current P(I). Our measurement method has high resolution and speed. For the first time we got a series of P(I) of NbN/AIN/AbN and Nb/AIOx/Nb at different temperatures from 4.2K to 30mK and within certain range the results match theoretical ones perfectly. With some other instruments, this method can be employed in the studies on more characteristics (such as Rabi oscillation) of Josephson junctions.