Electronic structure of iron-based superconductors with thick perovskite-blocking layers

Since superconductivity in LaFeAsO$_{1-x}$F$_x$ was found, various families of iron-based superconductors have been discovered. Recently, a new type whose blocking layer structure is perovskite-based has been reported, and Tc of this family has reached almost 40K. In this paper, we calculate electronic structures of the iron-based superconductors with thick perovskite layers by using first-principles density functional theory and compare them with those of other iron-based superconductors. We also discuss ability of application of those superconductors.