Studying the effects of ambient temperature, chemical potential and external magnetic field on the enhanced Faraday rotation in multilayered structures containing a hybridized topological insulator thin film

Abstract

In this paper, we insert a hybridized topological insulator thin film in a dielectric multilayered structure with a defect layer to enhance the Faraday rotation at the terahertz region as well as transmittance. By employing the transfer matrix method for anisotropic interfaces, it is demonstrated that Faraday rotation in this structure at defect modes is significantly stronger compared to the case at which the hybridized topological insulator layer used as a defect in the multilayered structure or a suspended topological insulator layer in air. The absolute value of positive Faraday rotation angle at defect modes for the transverse magnetic polarized incidence is so larger than one of negative Faraday rotation angle for the transverse electric polarized incidence. Furthermore, the dependence of Faraday rotation angle on the ambient temperature, external magnetic field and chemical potential is studied for both TE and TM polarizations. Faraday rotation at defect modes is diminished with increase of temperature and chemical potential. In some defect modes, Faraday rotation enhances with the increase of external magnetic field, while in others it first increases and then decreases.