Effect of dimensionality on shot-noise suppression in nondegenerate diffusive conductors

We present a theoretical investigation of shot-noise suppression due to lon g-range Coulomb interaction in nondegenerate diffusive conductors. Calculat ions make use of an ensemble Monte-Carlo simulator, self-consistently coupl ed with a one-dimensional Poisson solver. We analyze the noise in a lightly doped active region surrounded by two contacts acting as thermal reservoir s. The effect of momentum space dimensionality on shot-noise suppression is analyzed. Provided significant space-charge effects take place inside the active region, long-range Coulomb interaction is found to play an essential role in suppressing the shot noise at qU much greater than k(B)T. In the e lastic diffusive regime, dimensionality is found to modify the suppression factor gamma, which within numerical uncertainty takes values of about 1/3, 1/2 and 0.7 in the cases of 3, 2 and 1 dimensions, respectively. (C) 2000 Elsevier Science Ltd. All rights reserved.