Noise-Induced Hopping in an RF SQUID

An RF superconducting quantum interference device (RF SQUID), which is an important bistable system, has attracted much attention for its important applications in nonlinear fields. With different potential shapes at 20 mK, we perform detailed research on the relationship between the probability of the phase particle in the left potential well
$(P_{L})$
of an RF SQUID and the external noise intensity
$(D)$
, which provides a method to identify the symmetry of any tunable bistable systems. A qualitative model is proposed to understand the physical process, and the numerical results are well consistent with the experimental results.