Interpretation of a microwave induced current step in a single intrinsic Josephson junction on a Bi-2223 thin film

Thin stacks consisting of a single intrinsic Josephson junction on (Bi,Pb)- Sr-Ca-Cn-O thin films are investigated under the influence of external micr owave fields. The I-V-characteristic shows a single resistive branch, a cle ar superconducting gal, edge structure and a pronounced current step in ext ernal microwave fields. With increasing irradiation power it shifts to high er voltages, while the height of the step remains practically unchanged. In a numerical simulation including an ac-magnetic field parallel to the supe rconducting layers the experimental features of the structure can he explai ned by a. collective motion of Josephson fluxons.