The Fermi surface of Ba(1-x)K(x)Fe2As2 and its evolution with doping

TL;DR

This study uses ARPES to examine how the Fermi surface of Ba(1-x)K(x)Fe2As2 evolves with doping, revealing changes consistent with hole doping and validating FLAPW calculations for these materials.

Contribution

It provides detailed ARPES measurements of the Fermi surface evolution in Ba(1-x)K(x)Fe2As2 and confirms the applicability of FLAPW calculations for modeling its electronic structure.

Findings

Fermi surface consists of hole pockets at Gamma and electron pockets at X in BaFe2As2.

Doping with potassium expands hole pockets and shrinks electron pockets.

Fermi surface evolution aligns with a rigid band shift model.

Abstract

We use angle-resolved photoemission spectroscopy (ARPES) to investigate the electronic properties of the newly discovered iron-arsenic superconductor, Ba(1-x)K(x)Fe2As2 and non-supercondcuting BaFe2As2. Our study indicates that the Fermi surface of the undoped, parent compound BaFe$_2$As$_2$ consists of hole pocket(s) at Gamma (0,0) and larger electron pocket(s) at X (1,0), in general agreement with full-potential linearized plane wave (FLAPW) calculations. Upon doping with potassium, the hole pocket expands and the electron pocket becomes smaller with its bottom approaching the chemical potential. Such an evolution of the Fermi surface is consistent with hole doping within a rigid band shift model. Our results also indicate that FLAPW calculation is a reasonable approach for modeling the electronic properties of both undoped and K-doped iron arsenites.