We show that in a source-free subwavelength region of microwave fields, there can exist field structures with a local coupling between the time-varying electric and magnetic fields differing from the electric-magnetic coupling in regular-propagating free-space electromagnetic waves. To distinguish such field structures from regular electromagnetic (EM) field structures, we term them as magnetoelectric (ME) fields. We study a structure and conservation laws of microwave ME near fields. We show that there exist sources of microwave ME near fields-the ME particles. These particles are represented by small quasi-two-dimensional ferrite disks with magnetic-dipolar-oscillation spectra. The near fields originating from such particles are characterized by topologically distinctive power-flow vortices, nonzero helicity, and a torsion degree of freedom. The paper consists of two main parts. In the first one, we give a theoretical background of properties of the electric and magnetic fields inside and outside of a ferrite particle with magnetic-dipolar-oscillation spectra resulting in the appearance of microwave ME near fields. In the second main part, we represent numerical and experimental studies of the microwave ME near fields and their interactions with matter. Based on the obtained properties of the ME near fields, we discuss possibilities for effective microwave sensing of natural and artificial chiral structures.

Because of confinement phenomena, semiconductor quantum dots show typical atomic properties such as discrete energy levels and shell structures. The energy eigenstates are described based on the Schrödinger-like equation for the electronic envelope wavefunctions. From the point of view of fundamental studies, the reduction of dimensionality in microwave ferrites brings into play new effects, which should be described based on the quantized picture and demonstrate, as a fact, the properties of artificial atomic structures. The intermediate position of magnetic-dipolar (or magnetostatic) oscillations in ferrite samples between 'pure' electromagnetic and spin-wave (exchangeinteraction) processes reveals the very special behaviour of geometrical effects. In view of recent studies on the local-field effects for subwavelength systems, some aspects of magnetic-dipolar oscillations in a normally magnetized ferrite disc should be reconsidered based on macroscopically quantized methods. The purpose of this paper is to develop macroscopically quantized phenomenological models for magnetostatic-wave ferrite discs based on the Schrödinger-like equation.

There has been a surge of interest in the subwavelength confinement of electromagnetic fields. It is well known that, in optics, subwavelength confinement can be obtained from surface plasmon (quasielectrostatic) oscillations. In this article, we propose to realize subwavelength confinement in microwaves by using dipolarmode (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 at the origin of topological singularities resulting in Poynting vector vortices and symmetry breakings of the microwave near fields. We show that new subwavelength microwave structures can be realized based on a system of interacting MDM ferrite disks. Wave propagation of electromagnetic signals in such structures is characterized by topological phase variations. Interactions of microwave fields with an MDM ferrite disk and MDM-disk arrays open a perspective for creating engineered electromagnetic fields with unique symmetry properties.

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