Electronic structure, spin excitations, and orbital ordering in a three-orbital model for iron pnictides

Abstract

A three-orbital itinerant-electron model involving d _xz , d _yz and d _xy Fe 3d orbitals is proposed for iron pnictides towards understanding the ( $\pi ,0$ ) ordered magnetism and magnetic excitations in these materials. It is shown that this model at half filling yields a gapped ( $\pi ,0$ ) magnetic state, and simultaneously reproduces several experimentally observed features such as the electronic structure, spin excitations, as well as the ferro orbital order between the d _xz and d _yz orbitals.

Keywords

• iron pnictides
• magnetic excitations
• spin waves
• fermi surface
• orbital order