In gap states in topological Kondo insulators: Optical properties evidence*

We investigate optical properties: ARPES, PES and optical conductivity of topological Kondo insulators; in particular we study the manifestation of In gap states in the ARPES and PES results, taking into account the presence of antiferro-magnetic short range correlations. We consider an additional narrow band to the otherwise completely localized f-electrons, by adding a term to the periodic Anderson model which allows a small hopping of the localized electrons between neighboring sites of the lattice. This new model is adequate to study a novel class of intermetallic 4f and 5f orbitals materials: the Kondo topological insulators. For simplicity, we consider a version of the periodic Anderson model on a two dimensional square lattice. Previously we shows that the anti ferro-magnetic correlations plays an important role on the gap opening of the topological Kondo insulators (1); in this work we discuss the manifestation of the in gap states in the ARPES and PES results, our results for the different symmetry points are similar to the reported for SmB6 (2).
(1) E. Ramos et al.J. Phys. Condens. Matter 29 , 345601 (2017).
(2) M. Neupane et al, Nature Communications, DOI:10.1038/ncomms3991 (2013)