Dispersion of Volume Relativistic Magnetoplasma Excitation in a Gated Two-Dimensional Electron System

The dispersion of the volume relativistic magnetoplasma mode in a gated GaAs/AlGaAs quantum well is measured using a coupled resonators detection technique. The weakly damped relativistic mode exhibits an unusual zigzag-shaped magnetodispersion dependence dictated by the diagonal component of the resistivity tensor $\rho_{xx}$. The plasma excitation easily hybridizes with photon modes due to a large spatial delocalization of its electromagnetic field. The effects of electron density and structure geometry on the excitation spectrum have been investigated.