Lattice model calculations for d x2− y2-wave Josephson junctions

Abstract

The Josephson current–phase relations in d-wave/d-wave superconductor junctions in the tunnel limit are studied using the two-dimensional t- J model. The order parameters are determined in a self-consistent way within the Gutzwiller approximation and the Bogoliubov–de Gennes theory. We find that the anomalous current–phase relation in ( 1 1 0 ) junctions obtained within a quasiclassical theory is qualitatively reproduced with microscopic model calculations. Our method can be applied to grain boundary junctions in which the atomic scale roughness should be taken into account.