THEORY OF JOSEPHSON TUNNELING BETWEEN D-WAVE SUPERCONDUCTORS

Using a tightly-binding model, we present a Josephson tunneling theory for d-wave superconductivity. Unlike the conventional theory, the int erface influence on the wave functions of quasiparticles are taken int o account in the model. With the theory, we calculate the temperature dependence of the critical current of Josephson tunneling between YBCO high-T-c superconductors along the a-axis. It is shown that the exper imental mearurements can be excellently explained by the present model with pure d-wave symmetry. Meanwhile, we find that the contribution o f the s-wave component, though it may exist, is not significant to the ab-plane tunneling. Copyright (C) 1996 Published by Elsevier Science Ltd.