Density-functional calculations of the electronic structures and magnetism of thepnictide superconductors BaFeAs2 and BaFeSb2

Abstract

We investigate the structural, electronic, and magnetic properties of the hypothetical compound BaFePn(2) (Pn=As and Sb), which is isostructural to the parent compound of the high-temperature superconductor LaFeAsO1-xFx. Using density-functional theory, we show that the Fermi surface, electronic structure, and spin-density wave instability of BaFePn(2) are very similar to the Fe-based superconductors. Additionally, there are very dispersive metallic bands of a spacer Pn layer, which are almost decoupled from FePn layer. Our results show that experimental study of BaFePn(2) can test the role of charge and polarization fluctuation as well as the importance of two dimensionality in the mechanism of superconductivity.