Tellegen particles and magnetoelectric metamaterials

Abstract

In 1948 Tellegen ͓Philips Res. Rep. 3, 81 ͑1948͔͒ suggested that an assembly of the lined up electric-magnetic dipole twins can construct a new type of an electromagnetic material. Until now, however, the problem of creation of the Tellegen medium is a subject of strong discussions. An elementary symmetry analysis makes questionable an idea of a simple combination of two ͑electric and magnetic͒ dipoles to realize local materials with the Tellegen particles as structural elements. In this paper we show that in search of sources with local junctions of the electrical and magnetic properties one cannot rely on the induced parameters of small electromagnetic scatterers. No near-field electromagnetic structures and no classical motion equations for point charges give a physical basis for realization of sources with a local junction of the electrical and magnetic properties. We advance a hypothesis that local magnetoelectric ͑ME͒ particles should be physical objects with eigenmode oscillation spectra and nonclassical symmetry breaking effects. Our studies convincingly prove this assumption. We show that a quasi-two-dimensional ferrite disk with magnetic-dipolar-mode oscillations is characterized by unique symmetry features with topological phases resulting in appearance of the ME properties. An entire ferrite disk can be characterized as a combined system with the eigenelectric and eigenmagnetic moments. The fields near such a particle are distinguished by special symmetry properties. The questions raised in this paper give new insights into a problem of realization of local ME composites.

Manipulating microwaves with magnetic-dipolar-mode vortices

“…The magnetic-dipolar modes (MDMs) are characterized by energy eigenstates [1,2], gauge electric fluxes, and eigenelectric (anapole) moments [3]. Special vortex characteristics of MDMs in thin-film ferrite disks were found numerically and analytically [4,5]. The results give deep insight into an explanation of the experimental multiresonance absorption spectra shown both in previous [6,7] and new [8][9][10] studies.…”

“…Such a numerical analysis is well justified by our previous analytical and experimental studies of MDM vortices in small ferrite particles [4,5,9,10]. We analyze the field structures for the case of a single ferrite disk and ferrite-disk arrays placed inside a rectangular waveguide.…”

“…These approaches, distinguished by the differential operators and boundary conditions used for solving the spectral problem, give two types of the MDM oscillation spectra in a quasi-2D ferrite disk. Conventionally, these two approaches are named as the G-and L-modes in the magnetic-dipolar spectra [5,29].…”

“…Such vortex behaviors are well justified based on analytical solutions of the MDM spectral problem in a helical coordinate system [29]. With further reduction of the helical-system solutions to the cylindricalcoordinate solutions, one can use separation of variables so that the MS-potential wave function for L modes can be written as [4,5,29] ψ ν,n = Cξ ν,n (z)φ ν,n (r,θ ), (2) where a dimensionless effective membrane functionφ ν,n (r,θ ) is defined by the Bessel-function orders ν = 1,2,3, . .…”

Magnetic-Dipolar-Mode Oscillations for Near- And Far-Field Manipulation of Microwave Radiation

“…For the first time, the rotating field configurations and power-flow vortices inside a ferrite disk were shown for the L-mode spectra in Refs. [46,47]. Figures 5 and 6 show a typical configuration of rotating electrical and magnetic fields inside a ferrite disk for the 1st MDM.…”