Charge Density Wave and Spin Density Wave in Two-Orbital Model for Iron-Based Superconductors

Abstract

We present a mean-field theoretical model study for the coexistence of the two strongly interacting charge density wave (CDW) and spin density wave (SDW) for iron-based superconductors in the under-doped region before the onset of the superconductivity in the system. The analytic expressions for the temperature dependence of the CDW and SDW order parameters are derived by using Zubarev’s technique of double-time single particle Green’s functions and solved self-consistently. Their interplay is studied by varying both the CDW and SDW coupling constants. Further, the electronic density of states (DOS) for the conduction electrons are studied in the pure CDW and SDW states and coexistence state for the cases, where the CDW transition temperature is greater than the SDW transition temperature and vice versa, which show two gap parameters.