I clicked this and expected to read about new kinds of thermal paste or whatever, not to be slapped in the face with a whole field of solid state physics I'd ne

I clicked this and expected to read about new kinds of thermal paste or whatever, not to be slapped in the face with a whole field of solid state physics I'd never even heard of before (magnonics). I'd complain about being paywalled by the website but I'd probably not understand anything beyond the abstract (and even then, hardly). Can someone offer a dumbed-down explanation of this to someone who only barely understands Maxwell's equations?