Phase diagram of the two-dimensional 16-band d-p model for iron-based superconductors

摘要

The electronic state of the Fe_2As_2 plane in iron-based superconductors is investigated on the basis of the two-dimensional 16-band d-p model. Using the random phase approximation for the on-site Coulomb interaction between Fe d electrons, we obtain the phase diagram including the magnetic ordered states and the superconductivity. It is found that the s±-wave superconductivity, where the gap functions have different signs between the electron pockets and the hole pockets, is realized near the incommensurate magnetic ordered phase with q～(π,π). The absolute values of the gap functions on the Fermi surfaces are almost isotropic but largely depend on the energy bands.