Cavity optomagnonics with magnetic textures: coupling a magnetic vortex to light

Efforts so far in cavity optomagnonics, where light couples coherently to magnons in a solid state cavity system, have focused on systems with a homogeneous magnetic background. We propose a cavity-optomagnonic system with a non homogeneous magnetic ground state, namely a vortex in a magnetic microdisk. We study the coupling between optical whispering gallery modes to gyrotropic and flexural magnon modes localized at the vortex. We show that the optomagnonic coupling has a rich spatial structure and that it can be tuned by an externally applied magnetic field. Our results predict cooperativities at maximum photon density of the order of C ~ 0.01 by proper engineering of these structures.
Reference: J. Graf, H. Pfeifer, F. Marquardt, S. Viola-Kusminskiy; arXiv:1806.06727