METHOD AND SYSTEM FOR PRECISION MEASUREMENT OF THE CRITICAL CURRENT OF THE SIS-TYPE JOSEPHSON JUNCTION Russian patent published in 2023 - IPC G01R19/25 G01R33/35 

FIELD: measuring technology.

SUBSTANCE: invention relates to the field of measuring technology, and more specifically to methods for measuring the parameters of cryogenic electronic devices, in particular, to measuring the critical current of a SIS-type Josephson junction contact. A method is proposed for precision measurement of the critical current of a SIS-type Josephson junction placed in a refrigerator at a temperature below the critical one. To implement the method, an electric signal is formed using a current source in the form of a sequence of current pulses with increasing sections. Within the positive part of the rising sections of each pulse, the values of the voltage at the Josephson junction and the values of the current flowing through it are synchronously measured. The digital signal processing device sequentially compares the voltage values with the threshold value, determines the values of adjacent current samples and corresponding to the first exceeding the threshold value by voltage samples within each pulse and the previous sample. Then, among all the received current readings , the maximum value is determined, and among the readings , the minimum value. The value of the critical current is found as the average value between the obtained maximum and minimum current values.

EFFECT: reducing the measurement error of the critical current of the SIS-type Josephson junction, increasing the measurement speed and providing automatic measurement mode in digital form.

6 cl, 6 dwg, 1 tbl