Voltage–current and voltage–flux characteristics of asymmetric high T DC SQUIDs

The influences of the second harmonics together with the asymmetries of junctions on the voltage–current characteristics of high TC DC SQUIDs

“…Nevertheless, an unmistakable comparison (Fig. 3) between the experiment [19] and the analytic expressions confirms that the alone asymmetry considerations are not inclusive.…”

“…3. The red circles (black circles) show the results of our analytic expression considering only first harmonics in CPRs and D yellow 1 triangles (r green triangles) show the experimental results of Novikov et al [19] for SQUIDs with L $ 125-195 pH (L $ 65-75 pH). This figure shows that the formulation based on only the first harmonic, for the medium and the large inductance SQUIDs generally predicts larger values of exp(a/2)DV max /R and smaller values for the corresponding I m compared to the experimental data.…”

“…The theoretical and the experimental exp(a/2)DV max /R versus corresponding values of I m for 20 asymmetric SQUIDs of [19] are compared in Fig. 3.…”

Cryogenic low-noise amplifiers for measurements with superconducting detectors

“…The amplifiers are easy to mount to most of the measurement setups since they have a SMA termination. Unfortunately, modern cryostats for low-temperature experiments do not have a cooling temperature stage corresponding to 77 K. Hence, the designed amplifiers are most applicable for the working temperature of liquid nitrogen, which is the main working temperature for high-temperature superconducting sensors and semiconductor detectors [ 19 – 20 ].…”

Joint measurement of current-phase relations and transport properties of hybrid junctions using a three junctions superconducting quantum interference device

“…To measure reliably the CPR of the weak link one needs to consider a asymmetric SQUID where the supercurrent of the Josephson junction is much higher than the one of the weak link [7]. Taking into account the asymmetry of the junctions is generally an important point to understand the behaviour of DC SQUIDs [11][12][13]. In this geometry to unambiguously measure the conductance of one branch independently of the other, one technique consists in measuring the conductance of the SQUID, then opening one branch of the SQUID and measuring the conductance of the remaining branch and by subtraction, extract the conductance of the opened arm.…”