a-axis YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta///Au interface conductance-voltage characteristics

Conductance-voltage characteristics of interfaces between a-axis YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) thin films and gold are presented. When the gold counter electrode is deposited in-situ, the junctions have a specific interface resistivity in the 10/sup -9/ /spl Omega/-cm/sup 2/ range, about an order of magnitude lower than nominal in-situ, c-axis YBCO/noble-metal junctions. As with nominal c-axis YBCO/noble-metal junctions, there is clear evidence at T=4 K for a peak in the conductance at low bias. In addition, a dip in the the middle of the broad peak structure was resolved. It appears to be a feature unique to the a-axis YBCO/Au interface.