Evolution of Surface and Leaky Magnetopolaritons in Gyrotropic Semiconductors

Abstract

Propagation of “pure” surface waves (surface magnetopolaritons) along boundaries of semi-infinite gyrotropic and dielectric media has been considered by Wallis et al. in [1] (for semiconductors) and in [2] (for ferrites). Three types of configurations have been investigated there with different directions of the external magnetic field axis: H ₀ | | “surface” (Fig. 1a,b; Faraday and Voigt geometries) and H ₀ ⊥ “surface” (Fig. 1c). A “gap effect” (absence of surface-waves propagation in given intervals of the frequency ω and the propagation constant β′) has been established in two configurations: H ₀ | | “surface”; β′ | | H ₀ (Fig. 1a) and H ₀ ⊥ “surface”; β′ ⊥ H ₀ (Fig. 1c). Wallis et al. [1] have supposed that some type of “pseudo-surface” waves appears in these “gaps”. We have shown that a similar type of waves really exists [3], when the gyrotropic medium is semiconductor plasma. These leaky magnetopolaritons in Faraday geometry propagate along the magnetic-field axis with small attenuation and radiate perpendicularly to it.