Fluctuations of steps on crystal surfaces

Selke, W., Szalma, F., and Hager, J.S.
Technische Hochschule Aachen, Germany
Szeged University, Hungary
University of Maryland, USA


Fluctuations of isolated and pairs of ascending steps of monoatomic height are studied in the framework of SOS models, using mainly Monte Carlo techniques. Below the roughening transition of the surface, the profiles of long steps show the same scaling features for terrace and surface diffusion. For a pair of short steps, their separation distance is found to grow as t^1/3 at late stages. Above roughening, simulational data on surface diffusion agree well with the classical continuum theory of Mullins.