Paramagnetic Effect in High<i><i>T</i></i>_cSuperconductors -A Hint for<i>d</i>-Wave Superconductivity

Abstract

The paramagnetic effect found experimentally in some granular high temperature superconductors is explained by a model of a Josephson network of <em>d</em>-wave superconductors. The unusual microwave absorption characteristics of these systems is also explained in a consistent way. Finally, a new experiment is proposed to give a decisive test for <em>d</em>-wave superconductivity in high <em>T_c</em> superconductors.