Suppression of non-Poissonian shot noise by Coulomb correlation in ballistic conductors

Abstract

We investigate the current injection into a ballistic conductor under the space-charge limited regime, when the distribution function of injected carriers is an arbitrary function of energy Fc(«). The analysis of the coupled kinetic and Poisson equations shows that the injected current fluctuations may be essentially suppressed by Coulomb correlations, and the suppression level is determined by the shape of Fc(«). This is in contrast to the time-averaged quantities: the mean current and the spatial profiles are shown to be insensitive to Fc(«) in the leading-order terms at high biases. The asymptotic high-bias behavior for the energy resolved shot-noise suppression has been found for an arbitrary ~non-Poissonian! injection, which may suggest a new field of investigation on the optimization of the injection energy profile to achieve the desired noisesuppression level.