Optimal pump frequency for ac hysteretic SQUID

The recently discovered effect of suppression of noise by a strong periodic signal is observed and investigated in the model of real electronic device, representing an ac hysteretic superconducting quantum interference device (SQUID). This effect is characteristic for any electronic device of the trigger type, where transitions between adjacent states occur dynamically under the influence of a periodic signal. The effect appears as a weak dependence of temporal characteristics on noise intensity in a certain range of the pump signal frequency and through the existence of a signal-to-noise ratio maximum as a function of this frequency. The specific feature of the SQUID is the weak dependence of the voltage-flux characteristic on noise intensity in a certain range of parameters. The utilization of this effect by proper tuning the system parameters allows one to significantly improve the SQUID sensitivity.