Left/right asymmetry of the dipole field due to reflection from a periodic multilayer of a topological insulator and a columnar thin film

The problem of a vertical electric dipole radiating above a periodic multilayer whose unit cell comprises a layer of a topological insulator (TI) and a columnar thin film (CTF) was solved in order to investigate the left/right asymmetry of the total electric field in the far zone in the half-space containing the dipole. Occurring in a wide range of the polar observation angle, the left/right asymmetry of Eϕ is due to both the CTFs and the TI layers. Occurring in a narrow range of the polar observation angle, the left/right asymmetry of Eθ is entirely due to the TI layers. For presently available values of the magnitude of the surface admittance γTI of TIs, significant left/right asymmetry occurs if the number of unit cells in the periodic TI/CTF multilayer is high enough.