Electronic Structure and Doping in BaFe${}_2$As${}_2$ and LiFeAs: Density Functional Calculations

Abstract

We report density functional calculations of the electronic structure and Fermi surface of the BaFe${}_2$As${}_2$ and LiFeAs phases including doping via the virtual crystal approximation. The results show that contrary to a rigid band picture, the density of states at the Fermi energy is only weakly doping dependent and that the main effect of doping is a change in the relative sizes of the electron and hole Fermi surfaces as required by Luttinger's theory. This is a consequence of a change in As height with doping, in particular a shift of As towards Fe as holes are introduced in the Fe plane, as might be expected from simple ionic considerations. The main effect of doping is therefore a reduction in the degree of nesting of the Fermi surface. This provides a framework for understanding the approximate electron-hole symmetry in the phase diagrams of the Fe-As based superconductors.

Added result of calculation for SDW in stoichiometric LiFeAs

References in corpus (6)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Thorium-doping induced superconductivity up to 56 K in Gd1-xThxFeAsO
• Superconductivity at 25 K in hole doped $(L{a}_{1-x}S{r}_x)OFeAs$
• Origin of the ~150 K Anomaly in LaOFeAs; Competing Antiferromagnetic Superexchange Interactions, Frustration, and Structural Phase Transition
• Nernst effect of the new iron-based superconductor LaO${}_{1-x}$F${}_x$FeAs

Cited by in corpus (5)

• Structure and superconductivity of LiFeAs
• Magnetism Driven by Anion Vacancies in Superconducting $\alpha$--FeSe${}_{1-x}$
• Density functional study of BaNi${}_2$As${}_2$: Electronic structure, phonons and electron-phonon superconductivity
• Multiple Gaps and Superfluid Density from Interband Pairing in Iron Oxypnictides
• Electronic structure of LaFe1-xCoxAsO from first principle calculations