We formulate a scattering theory to study magnetic films in microwave cavities beyond the independent-spin and rotating wave approximations of the Tavis-Cummings model. We demonstrate that strong coupling can be realized not only for the ferromagnetic resonance (FMR) mode, but also for spin wave resonances (SWRs); the coupling strengths are mode dependent and decrease with increasing mode index. The strong coupling regime can be also accessed electrically by spin pumping into a metal contact.
@article{arxiv.1412.5809,
title = {Exchange Magnon-Polaritons in Microwave Cavities},
author = {Yunshan Cao and Peng Yan and Hans Huebl and Sebastian T. B. Goennenwein and Gerrit E. W. Bauer},
journal= {arXiv preprint arXiv:1412.5809},
year = {2015}
}