- Garcia, DR;
- Jozwiak, C;
- Hwang, CG;
- Fedorov, A;
- Hanrahan, SM;
- Wilson, SD;
- Rotundu, CR;
- Freelon, BK;
- Birgeneau, RJ;
- Bourret-Courchesne, E;
- Lanzara, A
Using angle-integrated photoemission spectroscopy we have probed the novel
LaO$_{0.9}$F$_{0.1}$FeAs superconductor over a wide range of photon energies
and temperatures. We have provided the first full characterization of the
orbital character of the VB DOS and of the magnitude of the d-p hybridization
energy. Finally, we have identified two characteristic temperatures: 90K where
a pseudogap-like feature appears to close and 120K where a sudden change in the
DOS near E$_F$ occurs. We associate these phenomena with the SDW magnetic
ordering and the structural transition seen in the parent compound,
respectively. These results suggest the important role of electron correlation,
spin physics and structural distortion in the physics of Fe-based
superconductors.