Stochastic resonance-based input circuits for SQUIDs

摘要

A model is reported of a novel frequency-tuneable superconductive amplifier based on stochastic resonance effect in 4-terminal SQUID. The model considers a controllable bistable oscillator with the potential barrier separating two metastable states of superconducting ring closed by a 4-terminal mesoscopic weak link. The barrier is governed by the transport current driven through the other two leads of the 4-terminal weak link. Numeric simulations show the stochastic resonance regime is achieved if some external noise and small sine signal are applied. The signal gain and frequency properties strongly depend then on the transport current. In addition, the stochastic-like resonance is observed when the SQUID is affected by a sine high-frequency signal instead of the white noise pumping.