Topological Transition Points in a Magnetic-Semiconductor Periodic Structure in an External Magnetic Field

Abstract

In this paper iso-frequency surfaces of a ferrite-semiconductor superlattice under an action of an external magnetic field are studied. The structure is considered in the subwavelength regime, when it is possible to introduce effective components of permittivity and permeability tensors. It has been shown that due to the peculiarities of the structure under study, a variety of topology forms arises. The topological transitions points from the open to the closed forms are revealed and discussed, in particular for the cases, when iso-frequency surfaces intersect and degenerate. The effective control over the topology states and topological transition points is possible by means of appropriate choice of the metamaterial constituent components and their properties, like material fractions, working frequency, value of the external magnetic field.