We have performed ab initio LDA calculations of electronic structure of newly discovered prototype high-temperature superconductors AFe_2As_2 (A=Ba,Sr) and compared it with previously calculated electronic spectra of ReOFeAs (Re=La,Ce,Pr,Nd,Sm). In all cases we obtain almost identical densities of states in rather wide energy interval (up to 1 eV) around the Fermi level. Energy dispersions are also very similar and almost two-dimensional in this energy interval, leading to the same basic (minimal) model of electronic spectra, determined mainly by Fe d-orbitals of FeAs layers. The other constituents, such as A ions or rare earths Re (or oxygen states) are more or less irrelevant for superconductivity. LDA Fermi surfaces for AFe_2As_2 are also very similar to that of ReOFeAs. This makes the more simple AFe_2As_2 a generic system to study high-temperature superconductivity in FeAs - layered compounds.
@article{arxiv.0806.2630,
title = {Electronic Structure of Prototype AFe_2As_2 and ReOFeAs High-Temperature Superconductors: a Comparison},
author = {I. A. Nekrasov and Z. V. Pchelkina and M. V. Sadovskii},
journal= {arXiv preprint arXiv:0806.2630},
year = {2009}
}
Comments
5 pages, 7 figures, v2: corrected typos and Fig. 6