Electronic structure of the BaFe2As2 family of iron-pnictide superconductors

We use high-resolution angle-resolved photoemission to study the electronic structure of the BaFe{sub 2}As{sub 2} pnictides. We observe two electron bands and two hole bands near the X point, ({pi},{pi}) of the Brillouin zone, in the paramagnetic state for electron-doped Ba(Co{sub 0.06}Fe{sub 0.94}){sub 2}As{sub 2}, undoped BaFe{sub 2}As{sub 2}, and hole-doped Ba{sub 0.6}K{sub 0.4}Fe{sub 2}As{sub 2}. Among these bands, only the electron bands cross the Fermi level, forming two electron pockets around X while the hole bands approach but never reach the Fermi level. We show that the band structure of the BaFe{sub 2}As{sub 2} family matches reasonably well with the prediction of local-density approximation calculations after a momentum-dependent shift and renormalization. Our finding resolves a number of inconsistencies regarding the electronic structure of pnictides