Rf-Induced Steps in Intrinsic Josephson Junctions in

Clark A. Hamilton

H.-D. Hahlbohm, A. Hoffmann, H. Lübbig +2 more

Akinobu Irie, Y. Kurosu, Gin-ichiro Oya

We have investigated the RF-induced steps in intrinsic Josephson junctions in mesa-shaped Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub y/ single crystals. By applying RF signal in the frequency range 2-20 GHz to the mesa, two types of responses were observed depending on the frequency of the applied microwave. One is the Shapiro step response observed at the frequencies above the Josephson plasma frequency for surface junction. Another is the microwave-induced vortex flow response for surface and inner junctions. We found that the junction size is also the key condition for the observation of Shapiro steps together with the frequency of applied microwave.

Sabino Maggi

The response of an overdamped current biased Josephson junction to a pulsed rf drive has been investigated by both numerical and analog simulations. The rf signal was a periodic rectangular pulse of varying amplitude and duration. A considerable increase of the width of the rf-induced steps with respect to those of an equivalent junction driven by a sinusoidal signal has been obtained. In the limiting case of a pulse repetition frequency much lower than the junction RC cutoff frequency, all steps have a maximum width which is independent of the step order n and increases with decreasing pulse duration.

Masahiko Machida, Takuma Kano, Susumu Yamada +3 more

S. Rother, R. Kleiner, Paul Müller +3 more