Theory for electron-doped cuprate superconductors:: d-wave symmetry order parameter

Using as a model the Hubbard Hamiltonian we determine various basic properties of electron-doped cuprate superconductors like Nd2-xCexCuO4 and Pr2-xCexCuO4 for a spin-fluctuation-induced pairing mechanism. Most importantly we find a narrow range of superconductivity and, similar to hale-doped cuprates dx(2)-y(2), symmetry for the superconducting order parameter. The superconducting transition temperatures T-c(x) for various electron doping concentrations x are calculated to be much smaller than for hole-doped cuprates due to the different energy dispersion and a flat band well below the Fermi level. Lattice disorder may sensitively distort the symmetry d(x2-y2) via electron-phonon interaction.