We report on an electronic structural study of BaFe2As 2 which has a spin-density-wave (SDW) transition and is a parent material of FeAs-based superconductors. Angle-resolved photoemission spectroscopy on BaFe2As2 shows that, across the SDW transition, the spectral weight at 0-100 meV below EF is reconstructed to form flat bands and Fermi surfaces in the SDW state. The coexistence of the Fermi surfaces and the flat band supports the orbital-dependent excitonic coupling between electron and hole pockets rather than the simple Fermi surface nesting as the origin of the SDW state.
- Excitonic coupling
- Iron pnictides
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering