Supercurrent-versus-magnetic field characteristics of two-dimensional Josephson tunnel junctions

Detailed measurements have been performed on the magnetic field dependence of ''large'' Nb-Nb/sub x/O/sub y/-Pb Josephson junctions in which the junction dimension in the direction parallel to the applied field is several times larger than the Josephson penetration depth. The results are discussed in the framework of an approximate analysis for two-dimensional tunnel junctions, based on the assumption of a linear current-phase relation. A size-reduction technique has been employed for the samples, to allow a consistent comparison betweeen ''large'' and ''small'' junction behavior