Magnetism and Superconductivity in the Two-Dimensional 16-Band d-p Model for Iron-Based Superconductors

The electronic states of the Fe2As2 plane in iron-based superconductors are investigated oil the basis of the two-dimensional 16-band d-p model Which includes file Coulomb interaction oil a Fe site: the intra-and inter-orbital direct terms U and U', the Hand's coupling J and the pair-transfer J'. Using the random phase approximation (RPA), we obtain the magnetic phase diagram including the stripe and the incommensurate order on the U'-J plane. We also solve the superconducting gap equation within the RPA and find that, for large J, the most favorable pairing symmetry is extended s-wave whose order parameter changes its sign between the hole pockets and the electron pockets, while it is d(xy)-wave for small J.