The coupling between the optical mode of an LC cavity and a magnetoplasmon is studied by terahertz transmission spectroscopy. The magnetoplasmons are created by etching a high-mobility two-dimensional electron gas into stripes. As a result, we identify three different regimes, depending on the plasmon frequency relative to the cavity frequency. We find a significant coupling to the cyclotron dispersion even in presence of screening of the electric field by the plasmon.
Paravicini-Bagliani, G. L., Scalari, G., Valmorra, F., Keller, J., Maissen, C., Beck, M., & Faist, J. (2017). Gate and magnetic field tunable ultrastrong coupling between a magnetoplasmon and the optical mode of an LC cavity. Physical Review B, 95(20). https://doi.org/10.1103/PhysRevB.95.205304