On-chip terahertz spectroscopy of magnetoplasmons in a two-dimensional electron gas

We report observations of magnetoplasmons at frequencies up to 400 GHz in gated two-dimensional electron gases (2DEG) at low temperature (∼ 2K). We observed bulk magnetoplasmons for frequencies greater than the cyclotron resonance frequency, and attributed resonances occurring at frequencies below the cyclotron resonance to formation of edge magnetoplasmons (EMPs). Our full-wave 3D electromagnetic simulation results are in good agreement with the experimental findings, allowing us to predict the spatial distribution of both bulk and edge magnetoplasmon modes in the 2DEG.