We report dissipative magnon-photon coupling caused by cavity Lenz effect, where the magnons in a magnet induce a rf current in the cavity, leading to a cavity back action that impedes the magnetization dynamics. This effect is revealed in our experiment as level attraction with a coalescence of hybridized magnon-photon modes, which is distinctly different from level repulsion with mode anticrossing caused by coherent magnon-photon coupling. We develop a method to control the in- terpolation of coherent and dissipative magnon-photon coupling, and observe a matching condition where the two effects cancel. Our work sheds light on the so-far hidden side of magnon-photon coupling, opening a new avenue for controlling and utilizing light-matter interactions.
@article{arxiv.1809.01233,
title = {Level Attraction Due to Dissipative Magnon-Photon Coupling},
author = {M. Harder and Y. Yang and B. M. Yao and C. H. Yu and J. W. Rao and Y. S. Gui and R. L. Stamps and C. -M. Hu},
journal= {arXiv preprint arXiv:1809.01233},
year = {2018}
}