Range of chaotic state in the Josephson junction driven by a pulse train signal

The parameter dependence of the onset of chaos which appears as the devil´s staircase on the current-voltage curve in the Josephson junction driven by a pulse train signal is studied based on an analog circuit simulation. In this study, hysteresis parameter /spl beta/ and reduced frequency /spl Omega/ are regarded as significant. It is suggested that from the viewpoint of these parameter dependencies there is no remarkable difference in the range of chaotic states in the junction if compared to a monochromatic-signal-driven junction, meaning that operation above the junction plasma frequency is desirable to avoid chaos. The rf-amplitude dependence of the onset of chaos is also roughly surveyed.