Orbital nature of the hole-like Fermi surface in superconducting Ba(Fe1−xCox)2As2

Abstract

We report a high-momentum and energy resolution angle-resolved photoemission study of superconducting Ba(Fe1−xCox)2As2. Polarization-dependent measurements performed at low photon energy along high-symmetry directions in the Brillouin zone made it possible to get new insight into the role of the five Fe 3d orbitals in the complex electronic structure of this compound close to the Fermi level, in particular, into the nature of the holelike pockets. Two distinct inner α pockets could be disentangled, suggesting that their origin is probably due to hybridized dxz and dyz. We also show that the complex outer β pocket is mainly of dz2 nature, with contributions of other orbitals of different symmetry only in specific points of the Brillouin zone, in the proximity of the kz=1 [4π/c] plane. The identification of a dz2 nature for β contributes to our understanding of the role of electron correlations in 122 pnictide superconductors and of the enhancement of the three-dimensional character of the Fermi surface in Co-doped compounds.

Source-reported materials — not catalogue approval

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