Existence of a metallic magnetically ordered state at intermediate Hubbard couplings in multi-orbital models for undoped iron pnictides

We present the results of a mean-field study for models that describe undoped iron pnictides. A realistic four-orbital model including iron $d_{xz}$, $d_{yz}$, $d_{xy}$, and $d_{x^2-y^2}$ orbitals is mainly discussed. Results for a two-orbital model with $d_{xz}$ and $d_{yz}$ orbitals are also shown. In both models, we report the existence of a novel intermediate coupling regime where the system is metallic and exhibits a striped spin order. Several properties of this state are discussed. By performing a mean-field study of other models for iron pnictides, we argue that such a metallic striped ordered phase is a general feature of the theoretical models describing iron pnictides.[1] \\[3pt] [1] R. Yu et al., submitted for publication.