Adatom diffusion by orchestrated exchange on semiconductor surfaces

Abstract
Recent experiments show that low temperature diffusion on semiconductor surfaces such as Ge(111) can be many orders of magnitude slower than expected. We present a model which provides a detailed explanation for the observed rate of diffusion on this surface. The effect is shown to be the result of complicated motions that allow surface adatoms to exchange places by hopping in an orchestrated manner between low-energy positions.