Scattered field from a dielectric-topological insulator rough interface using perturbation theory

摘要

Scattering from a dielectric-topological insulator (TI) rough interface is studied using perturbation theory (PT). Two models characterized by magneto-electric pseudo scalar Psi and surface admittance gamma for TI material are incorporated in the analysis. The zeroth order solution describes the reflection and transmission properties of the flat TI interface. Results are reported for various values of Psi and gamma. The Brewster angle is shifted while it occurs at 58 degrees for the dielectric case. The cross polarized reflection coefficients become small as the value of gamma is increased. The first order scattering coefficients represent the contribution by superimposed roughness on the flat interface. Numerical results show that for gamma-model, the first order co-polarized scattered field increases as gamma is increased while the cross polarized field decreases. It is noted that the model defined by gamma can better describe the scattering properties of the TI rough interface both theoretically and practically.