Magnon Waves on Chains of YIG particles: Dispersion Relations, Faraday Rotation, and Power Transmission

TL;DR

This paper investigates magnon wave propagation in chains of YIG particles, revealing dispersion relations, Faraday rotation effects, and potential for wireless power transfer, all within a quasistatic approximation framework.

Contribution

It provides the first detailed calculation of magnon dispersion relations and Faraday rotation in YIG particle chains, highlighting their potential for wireless power transmission.

Findings

Magnon waves exhibit dispersion relations similar to plasmonic waves.

Linearly polarized magnon waves undergo Faraday rotation during propagation.

Wireless power transmission via coupled magnon waves is feasible.

Abstract

We calculate the dispersion relations for magnon waves on a periodic chain of spherical or cylindrical Yttrium Iron Garnet (YIG) particles. We use the quasistatic approximation, appropriate when $kd \ll 1$, where $k$ is the wave number and $d$ the interparticle spacing. In this regime, because of the magnetic dipole-dipole interaction between the localized magnetic excitations on neighboring particles, dispersive magnon waves can propagate along the chain. The waves are analogous to plasmonic waves generated by electric dipole-dipole interactions between plasmons on neighboring metallic particles. The magnon waves can be longitudinal ($L$), transverse ($T$), or elliptically polarized. We find that a linearly polarized magnon wave undergoes a Faraday rotation as it propagates along the chain. The amount of Faraday rotation can be tuned by varying the off-diagonal component of the permeability tensor. We also discuss the possibility of wireless power transmission along the chain using these coupled magnon waves.