Dynamics of pulse driven Josephson junctions

It is demonstrated that the pulse-driven Josephson junction for high frequencies reacts in a similar way to the sinusoidally driven junction. At frequencies below the RC cutoff frequency, two distinct kinds of steps arise. The first is the usual series of Josephson steps. The second is a series of steps where the junction spends some time caught in the zero voltage basin of attraction, where a relaxation oscillation takes place. These steps are situated as substeps to the Josephson steps. Regions with seemingly chaotic motion are also observed