Microwave properties of large ion implanted niobium microbridges

Ion implantation has proved to be a reliable technique for fabricating thin film Josephson weak links suitable for practical applications. Moreover, ion implanted junction composed of a short and wide strip of a highly damaged superconductor linking two strongly superconducting banks models the intrinsic high-Tc intergranualar junctions much better then the tunnel junction model frequently recalled for that purpose. Therefore, the detailed understanding of the mechanism governing the behavior of an implanted microbridge is of an extreme and current importance. The most powerful tool for testing the physics and Josephson properties of a weak link is the microwave technique. In this paper the authors report on the detailed investigation on the behavior of microwave induced steps in the nitrogen implanted niobium microbridges possessing effective link dimensions large respect to the coherence length ξ