Implications of a d(x2-y2) Symmetry Component of the Order Parameter on Potential High-Tc Devices

Various experiments have indicated that the order parameter in the high-Tc cuprates has a predominant d(x2-y2) symmetry. This has important implications for devices based on Josephson junctions. The d(x2-y2) symmetry leads for example to intrinsic weak link formation, inhomogeneous current distributions in the junctions and reduced I(c) R(n) products. This article points out the implications a d(x2-y2) symmetry component has for Josephson junction devices, with particular emphasis on devices based on grain boundaries in high-Tc superconducting thin films.