DC SQUID - CURRENT NOISE

The computer model used by Tesche and Clarke to calculate the voltage noise across the dc SQUID is extended to calculate the circulating current noise around the SQUID loop, and the correlation between the circulating current noise and the voltage noise across the SQUID. The parameters chosen are {Mathematical expression}, and an applied flux of Φ0/4 (L is the SQUID inductance, I0 is the critical current per junction, T is the temperature, and Φ0 is the flux quantum). At frequencies well below the Josephson frequency and at the optimum current bias, the voltage power spectral density is approximately 16 kB TR, the current power spectral density is approximately 11kBT/R and the voltage-current correlation spectral density is approximately 12 kBT, where R is the resistance per junction. © 1979 Plenum Publishing Corporation.