SUPERCONDUCTING QUANTUM INTERFERENCE DEVICE.

Abstract

The actual sensitivity of a radio frequency SQUID, determined by fluctuations in the electrical degree of freedom and the preamplifier with selection of the working point between neighboring plateaus, is theoretically investigated. A standard method for describing regenerative systems, which operate in a conditionally stable mode, is used to describe the signal and noise characteristics of SQUID in this mode. Formulas are found for calculating the actual sensitivity of a SQUID with amplitude-phase demodulation of the output signal, and a camparison with the traditional 'on plateau' mode is performed.