Surface and bulk polaritons in a PML-type magnetoelectric multiferroic with canted spins: TE and TM polarization

Abstract

We present a theory for surface polaritons on ferroelectric-antiferromagnetic materials with canted spin structure. A small uniform canted moment is allowed, resulting in a weak ferromagnetism directed in the plane parallel to the surface. Surface and bulk polariton modes for a semi-infinite film are calculated for the case of transverse electric (TE) and transverse magnetic (TM) polarization. Example results are presented using parameters appropriate for BaMnF(4). We find that the surface modes are non-reciprocal for the TE polarization due to the magnetoelectric interaction, and the non-reciprocity can be controlled by an applied electric field. Example results for attenuated total reflection (ATR) are calculated. The magnetoelectric interaction also gives rise to 'leaky' surface modes in the case of TM polarization. These are pseudo-surface waves that exist in the pass band, and dissipate energy into the bulk of the material. We show that these pseudo-surface mode frequencies and properties can be modified by temperature and the application of external electric or magnetic fields.

Artificial ferroic systems: novel functionality from structure, interactions and dynamics

“…The weak ferromagnetism in a single phase material can support GHz frequency resonances and spin waves [181]. An alternative approach is to consider composites based on ferromagnetic materials which have technological applications in the MHz and GHz regimes.…”

New Class of Surface Magnon Polaritons in Enantiomeric Antiferromagnetic Structures

“…Unlike that, in the next interval 1 + χ < ε < (1 − ζ) −1 , where µ 1 < 1, the dispersion curve begins at cut-off frequency ω 1 (see Figure 3(b)). In both these cases, the section of the dispersion curve corresponding to SMP is given by the same Equations (21), (22). It is easily to see that in the interval of ε(1 − ζ) −1 < ε < (1 + χ)(1 − ζ) −1 , that is, when 1 < µ 1 < 1 + χ (Figure 4(a)), the wave has no resonance frequency (ω 2 2 < 0).…”

“…Among various types of surface polaritons, the surface magnon polaritons (SMP) propagating along an interface between a magnetic medium and other magnetic or nonmagnetic one, play an important role and represent a highly dynamic research area [16][17][18][19][20][21][22]. At present, SMP are widely used in several areas of science and technology, particularly in near-field spectroscopy of magnetic materials as well as in spintronic devices.…”

Electrodynamics of Magnetoelectric Media and Magnetoelectric Fields

“…By combining Maxwell's equations with the ME dynamical‐response parameters, different ME electrodynamics problems are formulated. There are, for example, studies of optical effects in ME materials, microwave ME phenomena of skyrmions, ME optical waveguide modes, ME polaritons, and canonical quantization of macroscopic electrodynamics in an ME medium …”