JOSEPHSON COUPLING AND THE MAGNETISM IN D-WAVE SUPERCONDUCTORS

We discuss the effect of the magnetic order for the Josephson junction of a d-wave superconductor. The presence of the magnetic order in the basal plane of a uniaxial crystal breaks the symmetry of the system a nd thus removes a rotational degeneracy in the d-wave superconducting order parameter. We calculate an effective Josephson coupling constant in the Ginzburg-Landau theory, when the order parameters are misorien ted across the junction. It is found that the critical current is a de creasing function of the misorientation angle in the weak coupling reg ion. The model can be applied to the heavy fermion superconductor UPt3 , in particular.