SURFACE-DIFFUSION LENGTH UNDER KINETIC GROWTH-CONDITIONS

We obtain, using both a direct numerical simulation and a kinetic scaling argument, the atomistic surface diffusion length under kinetic growth conditions such as molecular beam epitaxy. The diffusion length shows strong crossover effects arising from two different physical mechanisms: The number of adatoms (two or three) in the stable islands which define incorporation, and the ratio of the atomistic deposition rate (high or low) to the atomistic hopping rate at the growth front. We give detailed results for the functional dependence of the diffusion length on the growth rate.