Topological state and some physical properties of ScX (X= Sb and Bi) nano-layers

Abstract

In this work, some physical properties of ScX (X = Sb and Bi) nano-layers are evaluated based on DFT employing Wien2k code within generalized gradient approximation in presence of spin orbit coupling. The band order and topological phase of ScX (X = Sb, Bi) bulks are investigated and then the topological nature of these bulks is examined by the investigation of surface states topological phase of ScX nano-layers with different thicknesses. The bonding type between the surface atoms of ScX nano-layers is also investigated. Furthermore, the optical properties of ScX nano-layers are investigated and compared. The results show the high contribution of intraband transitions and consequently high reflectivity and negative real part of dielectric function of these nano-layers near zero energy. The different responses of ScX nano-layers to the radiated electromagnetic waves in polarizations of parallel and perpendicular to their surfaces imply the anisotropic optical features of these nano-layers in x (or y) and z directions. © 2020 Elsevier B.V.