ON THE THEORY OF THE RF PUMPED DOUBLE SQUID

A calculation is presented which described the behavior of a double SQUID, i.e., an RF-SQUID in which a DC-SQUID is used instead of the weak link. Account is taken of possible differences between the individual critical currents of the two weak links, and the asymmetrical current feed of the DC-SQUID. The very interesting property of this two quantization loop system to change its behavior in superimposed DC and RF magnetic fields depending on its parameter set values is discussed. From this analysis, the output characteristics of this novel SQUID configuration for use as an instrument for delicate measurements are computed, and the two RF pump modes are optimized via the double SQUID parameter set.