VORTEX MOTION AND JOSEPHSON EFFECT IN SUPERCONDUCTING MICROBRIDGES IN (001) and (105) ORIENTED YBazCu307-s THIN FILMS

Abstract-- Microbridges with dimensions smaller than the effective penetration depth XI, have been pre-pared in epitaxially grown (001) and (105) oriented YBa2Cu&7-6 thin films. The current-voltage charac-teristics of these bridges show specific kinks and steps which can be attributed to discrete coherent vortex mo-tion along single or multiple paths across the micro-bridges. The critical current of a configuration with two very small microbridges in parallel, shows periodic SQUID modulation a t 4.2 K. The preparation of high T, superconductor thin film structures with very small dimensions is important for measuring very local transport properties of the super-conductor, e.g. across grain boundaries, for the reali