Coexistence of SC and AFM in two-orbital model for s±-wave iron based superconductors

Abstract

The gap structure and pairing mechanism for iron based superconductors is hotly discussed as a central issue since their discovery. The long range order parameters, electronic specific heat, conduction electron density of states and energy band structure of iron based superconductors are calculated by a tight-binding two-orbital model with the coexistence of superconductivity and antiferromagnetism. We have proposed here a s±-wave pairing symmetry of the form cos kx × cos ky in a two-orbital model for the coexistence of the two order parameters in the mean-field approximation. The model is solved by Zubarev's double-time Green's function technique to find their self-consistent gap equations and are solved self-consistently numerically.