Complex dynamical behavior in RCL-shunted Josephson tunnel junctions

We report an extensive numerical study of-the nonlinear dynamical effects in Josephson tunnel junctions externally shunted by a resistor and an inductor in series. In the three-dimensional parameter space composed of the junction capacitance C, shunt inductance L, and the bias current I, we found the dynamics of the system extremely rich. At relatively low inductance L, we observe period doubling as well as an intermittency route to chaos. At higher values of the inductance, long chaotic transients were observed. We also studied the effect of thermal Johnson noise in the circuit and discuss the implications of our results in experiments using real Josephson tunnel junctions.