Magnetic-dipolar-mode vortices and microwave subwavelength metamaterials

Abstract

There has been a surge of interest in the subwavelength confinement of the electromagnetic fields. It is well known that in optics the subwavelength confinement can be obtained due to surface plasmon (quasielectrostatic) oscillations. In this paper we propose to realize the subwavelength confinement in microwaves due to dipolar-mode (quasimagnetostatic) magnon oscillations in ferrite particles. Our studies of interactions between microwave electromagnetic fields and small ferrite particles with magnetic-dipolar-mode (MDM) oscillations show strong localization of electromagnetic energy. MDM oscillations in a ferrite disk are origins of topological singularities resulting in Poynting-vector vortices and symmetry breakings of the microwave near fields. We show that new subwavelength microwave metamaterials can be realized based on a system of interacting MDM ferrite disks. The volume- and surface-wave propagation of electromagnetic signals in the proposed dense metamaterials will be characterized by topological phase variations. The MDM-particle-metamaterial concept opens a significantly new area of research. In particular, there is a perspective for creation of engineered electromagnetic fields with unique symmetry properties.