Fiske resonances in annular Josephson junctions

The resonances in two-dimensional annular Josephson junctions have been inv estigated from both a theoretical and experimental point of view. We obtain ed the analytical expression for the amplitude modulation of the Fiske reso nances in the case of an externally applied magnetic field and the determin ation of the voltage positions of the Fiske steps as a function of the junc tion geometrical parameters (inner and outer radius). The experiments have been carried out on Nb-based annular junctions with finite ring width. The dependence of the maximum amplitude of the first and second Fiske step as a function of the external magnetic field is investigated in detail for a wi de range of ring widths. The agreement found between experiments and the th eoretical model is excellent.