Observation of terahertz radiation from higher-order two-dimensional plasmon modes in GaAs/AlGaAs single quantum wells

Abstract

We have observed terahertz (THz) radiation from higher-order two-dimensional (2D) plasmon modes in GaAs/AlGaAs single quantum wells by time-resolved THz emission spectroscopy. Up to fifth-order plasmon modes are clearly resolved and the observed mode frequencies are in excellent agreement with theory. Relaxation times of the 2D plasmon modes are found to be almost independent of the plasmon wave vector accessible in the present experiment.