Imaging Of Magnetoplasmons Excited In A Two-Dimensional Electron Gas

We report on the direct observation of magnetoplasmon modes that are excited in a laterally confined two-dimensional electron gas (2DEG) by microwave radiation. The magnetoplasmon polaritons were imaged using spatially resolved photoluminescence (PL) spectroscopy of GaAs heterostructures, and their dependence on an external magnetic field and 2DEG density were studied. The PL pattern formation originates in the PL spectrum modulation by electrons that are heated by the local electric field of the magnetoplasmons. We revealed remarkable spatial oscillations of the microwave electric field in the samples containing a high mobility 2DEG.