Theory and Control of Multiple Hopping in Activated Surface Diffusion

Abstract

The theory of activated diffusion is reviewed. Results are presented for the one dimensional model of a particle moving on a periodic lattice coupled to a dissipative bath. Special attention is paid to the exponential hopping limit, which is of interest in experimental studies of metal atom diffusion on metals. Quantum effects, such as the suppression of diffusion through tunneling and above barrier reflection are discussed. New results are presented for the quantum theory in the exponential hopping limit. The control of diffusion via external fields is discussed as well as other open questions which remain unsolved.