Preparation of superconducting weak links in molybdenum films by ion implantation

We have implanted patterns of N+ and/or S+ ions into Mo films so as to produce structures in which two heavily-doped Mo regions with relatively high transition temperature Tcare connected by a short (\sim 1\mum) lightly-doped Mo region with lower transition temperature T'c. Near T'cthe lightly-doped region acts as a weak link between the heavily doped regions and passes a supercurrent having an oscillatory "diffraction pattern" dependence on magnetic field similar to that of Josephson tunnel junctions.