Closed-Loop Graphene-FET for High Harmonics THz Emission

Abstract

Graphene devices are known to have the potential to detect, generate, and manipulate THz radiation. In particular, graphene field-effect transistors have been proposed as suitable devices to host plasmonic instabilities that lead to the emission of THz; for instance, Dyakonov-Shur instability which relies upon direct current excitation. In our work, we propose a closed-loop scheme with positive feedback, in which a fraction of the source current is added to the imposed drain current. Thus, our simulations show that such mechanism can achieve faster saturation of the unstable modes, and, more importantly, an order of magnitude increase in the power of the higher modes.