Spin Cavitronics with YIG
Gerrit E.W. Bauer (Institute for Materials Research, Tohoku University, Sendai Japan)

The magnetic order parameter interacts with external fields of electromagnetic or elastic origin. The coupling can be enhanced when the field is confined to cavity, e.g. a square well potential with discrete bound states and large field amplitudes. The standard example is a microwave cavity consisting of a closed space with conducting boundaries. More generally, any object with sufficiently large dielectric constant that acts as an antenna can be interpreted as a cavity. Spin cavitronics addresses the physics and technology of spintronic materials and devices in cavities.
Yttrium iron garnet (YIG) is a ferrimagnetic electrical insulator with high Curie temperature and magnetic quality that make it an ideal material to study magnetization dynamics.
Here I will expand on the spin cavitronics of YIG films and spheres for microwave and for near infrared laser radiation, for which quite a number of experiments has been published in recent years.