Features of optical properties of semimetallic compounds ScBi and YBi

The results of experimental studies of the optical properties of binary cubic compounds ScBi and YBi are presented. The features of the frequency dispersion of dielectric functions in the wavelength range 0.22–15 $\mu$m are determined. The anomalous behavior of spectral characteristics in the infrared region of the spectrum corresponds to the semimetallic nature of these materials. A weak intraband contribution to low-energy optical conductivity is associated with the main feature of their electronic structure - the localization of the Fermi level in the region of a deep minimum of the density of states. The features of quantum light absorption are discussed on the basis of a comparative analysis of experimental and theoretical spectra of interband optical conductivity.