Magnetic metasurfaces with metallic inclusions

Abstract

Purpose of this paper is the development and creation of the magnetic metasurfaces with metallic inclusions operating both in the microwave and terahertz frequency ranges. Methods. The Maxwell’s equations and the expressions for the effective medium parameters are used to build the analytical models of the magnetic metasurfaces based on either a ferromagnetic (FM) or antiferromagnetic (AFM) dielectric matrix, containing a two-dimensional periodic structure of thin metal (non-magnetic) wires surrounded by insulators. Numerical simulation of such structures operating in the microwave range is carried out using the MaxLLG software package. The magnetron sputtering, liquid etching, optical lithography, and lift-off photolithography are used to create bicomponent magnetic metasurfaces, consisting of two magnetic materials with very different values of magnetization. The study of linear and nonlinear characteristics of the bicomponent magnetic metasurfaces is carried out using the methods of microwave and Brillouin spectroscopy. Results. Based on the developed analytical model of the magnetic metasurface with metallic (nonmagnetic) inclusions it is shown that the FM metasurface possesses properties of a left-handed medium in a microwave range and the AFM metasurface possesses similar properties in a terahertz range. In the last case, the material parameters of the AFM metasurface are twice negative in two frequency bands. For the magnetic metasurfaces with metallic magnetic inclusions, the formation of absorption bands in the spectrum of a traveling magnetostatic surface spin wave due to the resonant properties of the inclusions has been established. In the nonlinear regime, the effect of nonreciprocal parametric three-wave resonance was obtained. Conclusion. The results presented in the paper demonstrate a number of physical phenomena that are observed only in the magnetic metasurfaces with metallic (nonmagnetic and magnetic) inclusions.