Signatures of Hundness in kagome metals
Li Huang, Haiyan Lu
Abstract
By means of the density functional theory in combination with the dynamical mean-field theory, we tried to investigate the electronic structure of hexagonal FeGe, in which the Fe atoms form a quasi-two-dimensional layered kagome lattice. We predict that it is a representative kagome metal characterized by orbital selective Dirac fermions and extremely flat bands. Furthermore, Fe's $3d$ electrons are strongly correlated. They exhibit quite apparent signatures of electronic correlation induced by Hund's rule coupling, such as spin-orbital separation with non-Fermi-liquid behavior and spin freezing at intermediate temperature. Thus, hexagonal FeGe can be regarded as an ideal platform to study the interplay of kagome physics and Hundness.