Effects of interface roughness on d-wave Josephson junctions

The Josephson current–phase relations in d-wave/d-wave superconductor junctions in the tunnel limit are studied using the two-dimensional extended-Hubbard model. The order parameters are determined in a self-consistent way within the Bogoliubov-de Gennes theory. In this study, we calculate the case of (110) oriented junction which have the atomic scale roughness on their interfaces. In uniform junctions, the anomalous current–phase relation obtained within a quasiclassical theory is qualitatively reproduced. On the other hand, in the junctions with an interface impurity, that anomalous relation disappears.