NUMERICAL SIMULATIONS OF LONG JOSEPHSON-JUNCTIONS DRIVEN BY LARGE EXTERNAL RADIOFREQUENCY SIGNALS

There is experimental evidence in long Josephson junctions of rf-induced dynamical states that are not observed in small junctions. Such states consist of groups of current steps, asymmetrical with respect to the McCumber curve, having amplitudes much larger than the expected rf-induced (Shapiro) steps. Numerical solutions of the model equation (the perturbed sine-Gordon equation) obtained from the multimode expansion are in good agreement (at least qualitatively) with the experimental data. The basic dynamic configuration consists of multifluxon bunches phase locked to the rf signal. © 1990 The American Physical Society.