Diagonal and Off-Diagonal Contributions to Autocorrelation of Velocity Fluctuations in Semiconductors

Abstract
A theoretical analysis of velocity fluctuations in semiconductors is presented, and results obtained from a Monte Carlo procedure are shown for Si. It has been found in particular that (i) off-diagonal contributions to the velocity autocorrelation function must be taken into account; (ii) the convective contribution is positive; and (iii) a long tail in the autocorrelation function, due to intervalley fluctuations, may be present.