All-high <i>T</i> <i>c</i> Josephson tunnel junction: Ba1−<i>x</i>K<i>x</i>BiO3/Ba1−<i>x</i>K<i>x</i>BiO3 junctions

Abstract

We have fabricated all-high Tc superconducting tunnel junctions in the material Ba1−xKxBiO3. The junctions are of very high quality and have a Josephson supercurrent. For the low-resistance junctions, the IcR product approaches the theoretical limit.