Shot Noise Suppression in Quasi-One-Dimensional Field-Effect Transistors

Abstract

We present a novel method for the evaluation of shot noise in quasi-1-D field-effect transistors, such as those based on carbon nanotubes and silicon nanowires. The method is derived by using a statistical approach within the second quantization formalism and allows the inclusion of both the effects of Pauli exclusion and Coulomb repulsion among charge carriers. This way, it extends the Landauer-Buttiker approach by explicitly including the effect of Coulomb repulsion on noise. We implement the method through the self-consistent solution of the 3-D Poisson and transport equations within the nonequilibrium Green's function framework and a Monte Carlo procedure for populating injected electron states. We show that the combined effect of Pauli and Coulomb interactions reduces shot noise in strong inversion down to 23% of the full shot noise for a gate overdrive of 0.4 V, and that neglecting the effect of Coulomb repulsion would lead to an overestimation of noise up to 180%.