A new and very efficient mechanism of interlayer mass transport was identified which bypassed the Schwoebel-Ehrlich barrier to the diffusion of atoms over step edges. A channel for rapid mass transport was found to open up when a 2-dimensional island, randomly walking on a surface, touched the boundary of a descending step. The decay rate of the island then increased by about 2 orders of magnitude. Entire mounds could disappear very quickly, due to ledge contact events that were caused by the equilibrium fluctuations of step edges.

Fast Decay of Adatom Islands and Mounds on Cu (111): A New Effective Channel for Interlayer Mass Transport M.Giesen, G.S.Icking-Konert, H.Ibach: Physical Review Letters, 1998, 80[3], 552-5