Stochastic amplification of weak signals in an RF SQUID with ScS contact

Abstract

The paper presents results of a numerical simulation of the stochastic dynamics of magnetic flux in an RF SQUID loop with a Josephson point (ScS) contact driven by a mix of band-limited Gaussian noise and low-frequency small-amplitude sine signal, at finite temperatures $0<T<T_{c}$. A change in the gain of the stochastically amplified weak signal with the temperature rise is shown to be due to smearing of the energy barrier between adjacent metastable current states of the loop. A comparison to an RF SQUID with a tunnel (SIS) junction is done.