Experimental observation of induced stochastic transitions in a multiwall potential of an rf-SQUID loop

Experimental observation of a weak low-frequency harmonic signal in a point (superconductor-constriction-superconductor, ScS) contact superconducting quantum interference device (rf-SQUID loop), being amplified due to the stochastic transitions between two or more metastable states of the loop, under the influence of applied noise flux of varying intensity (the effect of stochastic resonance, SR). In addition to the usual SR effect found in a bi-stable system with Gaussian noise, there were observed transitions between several metastable states of the multiwell SQUID loop potential, due to the influence of binary noise, which can be interpreted as a kind of noise “spectroscopy” of the loop's metastable states, with varying values of trapped magnetic flux.