Analog Simulation on Enhanced ac Josephson Effect for Junction Driven by Pulse Train Current

The enhanced ac Josephson effect is studied based on an analog simulation when the junction is driven by an rf-signal source. On the basis of the resistively shunted Josephson junction model driven by a pulse train current, larger rf-induced current step-heights in the current-voltage characteristics were obtained in comparison with those obtained by a monochromatic sinusoidal drive. This result is considered to be originated by the harmonics of the rf-signal. In addition, the maximum value of the step-height is independent on the step number