Eur. Phys. J. B (2017) 90: 59
https://doi.org/10.1140/epjb/e2017-70609-7

Regular Article

Spin waves on chains of YIG particles: dispersion relations, Faraday rotation, and power transmission

¹ Department of Physics, The Ohio State University, Columbus, 43210 Ohio, USA
² Department of Physics, University of Liege, 4000 Liege, Belgium

^a e-mail: stroud@mps.ohio-state.edu

Received: 14 October 2016
Received in final form: 16 December 2016
Published online: 27 March 2017

Abstract

We calculate the dispersion relations for spin waves on a periodic chain of spherical or cylindrical Yttrium Iron Garnet (YIG) particles. We use the quasistatic approximation, appropriate when kd ≪ 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 spin 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 spin waves can be longitudinal (L), transverse (T), or elliptically polarized. We find that a linearly polarized spin 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 spin waves.