Interaction between microwaves and a single vortex in a long Josephson tunnel junction

The effects of microwave radiation on the vortex modes of Josephson tunnel junctions have been examined. Current steps are induced on the resistive branches at voltages V=(n/m)(hν/2e) where n and m are integers and ν is the frequency of the incident radiation. The system we have studied is a well-defined one in which vortices undergoing periodic motion interact with the periodic perturbation of the microwave radiation. Vertical steps are induced when resonance occurs.