Abstract
We analyze the metallic antiferromagnetic state of a five-orbital model for iron superconductors. We find that with increasing interactions the system does not evolve trivially from the pure itinerant to the pure localized regime. Instead we find a region with a strong orbital differentiation between and , which are half-filled gapped states at the Fermi level, and itinerant , , and . We argue that orbital ordering between the and orbitals arises as a consequence of the interplay of the exchange energy in the antiferromagnetic direction and the kinetic energy gained by the itinerant orbitals along the ferromagnetic direction with an overall dominance of the kinetic energy gain. We indicate that iron superconductors may be close to the boundary between the itinerant and the orbital differentiated regimes and that it could be possible to cross this boundary with doping.
- Received 9 August 2012
DOI:https://doi.org/10.1103/PhysRevB.86.174508
©2012 American Physical Society