Terahertz generation by plasma waves in nanometer gate high electron mobility transistors

A resonant voltage tuneable radiation (0.4 THz-1.0 THz) from the gated two dimensional electron gas in a 60 nm InGaAs field effect transistor was investigated. We show that (i) the observed emission appears once the drain-to-source voltage, U DS , exceeds the threshold value, U TH ; (ii) the resonant frequency can be tuned by U DS in agreement with the current driven plasma instability model of Dyakonov and Shur; (iii) by applying a quantizing magnetic field one increases U TH linearly with the magnetic field while the evolution of the emission signal is approximately a universal function of (U DS - U TH ).