Ion implantation into Nb/Nb oxide/PbAuIn Josephson tunnel junctions

Boron ions have been implanted into complete planar and edge Nb/Nb oxide/PbAuIn Josephson tunnel junctions to directly trim the Josephson current I0. Implantation caused reproducible increases in I0 and in the junction subgap conductance and decreases in the junction energy gap voltage Vg. The variations in junction properties were monotonic with 11B implant dose. Trimming of I0 was optimized when the 11B ions were implanted with the depth distribution peaked near the tunnel barrier.