Experimental observation of induced stochastic transitions in multi-well   potential of RF SQUID loop
  An amplification of a weak low-frequency harmonic signal is experimentally observed in a single-junction-superconducting quantum interferometer (RF SQUID loop) due to stochastic transitions between two or more metastable states of the loop under the applied noise flux of varying intensity (the effect of stochastic resonance, SR). In addition to the usual scenario of the SR in a bistable system with Gaussian noise, the transitions between multiple metastable states of the multi-well SQUID loop potential under the influence of a binary noise is observed. This can be interpreted as a kind of noise "spectroscopy" of the metastable states of the SQUID loop with different values of the trapped magnetic flux. 
O.G. Turutanov, V.Yu. Lyakhno, V.I. Shnyrkov
cond-mat.supr-con