Noise analysis of plasma wave oscillations in InGaAs channels

Nanometric InGaAs‐based High Electron Mobility Transistors (HEMTs) have been shown experimentally to generate and detect THz radiation. The observed phenomena can be attributed to the presence of plasma waves inside the transistor channel. To investigate these oscillations we have performed Monte Carlo simulations of InGaAs homogeneous channels of different length and thickness. To detect the presence of plasma waves we have calculated the spectral density of voltage fluctuations under thermodynamic equilibrium at 300 K. Results confirm the presence of 3D and 2D plasma modes according to the topology of the channel.