Symmetry of pair potential and Josephson effect in dirty SNS junctions

We derive a formula of the dc Josephson current between two superconductors with the anisotropic pairing symmetry. One of the basic characters in the junctions of the anisotropic superconductors is the formation of the zero-energy bound states at the junction interfaces, which leads to the low-temperature anomaly of the Josephson current. The contribution of the zero-energy states to the Josephson current is fully taken into account in the present formalism. We apply the formula to superconductor/dirty normal conductor/superconductor junctions. It is found that the ensemble average of the Josephson current vanishes when the junction interface is perpendicular to a plane which includes the node lines of the quasiparticle's excitation gap. (C) 2002 Elsevier Science B.V. All rights reserved.