Influences of broken time-reversal symmetry on the d.c. Josephson effects in d-wave superconductors

Abstract

In order to examine the influences of the spatial dependence of the pair potential, the d.c. Josephson current in d-wave superconductors is calculated using self-consistently determined pair potentials. The results show that the suppression of the d-wave pair potential near the insulator does not have serious effect on the properties of the Josephson current. On the other hand, drastic changes are obtained due to the inducement of a subdominant s-wave component, which spontaneously breaks time reversal symmetry. Especially, a rapid enhancement of the Josephson current at low temperature predicted in previous formulas is strongly suppressed.