We present a polarization-resolved study of the low-energy band structure in the optimally doped iron pnictide superconductor Ba 0.6K 0.4Fe 2As 2 (T c=37 K) using angle-resolved photoemission spectroscopy. Polarization-contrasted measurements are used to identify and trace all three low-energy holelike bands predicted by local density approximation (LDA) calculations. The photoemitted electrons reveal an inconsistency with LDA-predicted symmetries along the Γ-X high-symmetry momentum axis, due to unexpectedly strong rotational anisotropy in electron kinetics. We evaluate many-body effects such as Mott-Hubbard interactions, which are likely to underlie the anomaly, and discuss how the observed deviations from LDA band structure affect the energetics of iron pnictide Cooper pairing in the hole-doped regime.
|Physical Review B - Condensed Matter and Materials Physics
|Published - Oct 15 2012
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics