Theory of the microwave-soliton or antisoliton interaction in Josephson tunnel junctions

Recently, microwave-induced harmonic and subharmonic structures were observed on the resistive branches associated with soliton or antisoliton propagations in a long Josephson tunnel junction. We have calculated the microwave-power dependence of the induced step-structure heights using a perturbation method. It is found that for different steps, the power dependences are different. Furthermore, for a given step, the height as a function of the microwave power also depends upon the nature of the coupling of the microwaves to the junction which can be either electric or magnetic.