Fluctuations of isolated and confined surface steps of monatomic height.

Abstract

The temporal evolution of equilibrium fluctuations for surface steps of monatomic height is analyzed studying one-dimensional solid-on-solid models. Using Monte Carlo simulations, fluctuations due to periphery diffusion (PD) as well as due to evaporation and condensation are considered, both for isolated steps and for steps confined by the presence of straight steps. For isolated steps, the dependence of the characteristic power laws, their exponents, and prefactors on temperature, slope, and curvature is elucidated, with the main emphasis on PD, taking into account finite-size effects. The entropic repulsion due to a second straight step may lead, among other things, to an interesting transient power-law-like growth of the fluctuations, for PD. Findings are compared to results of previous Monte Carlo simulations and predictions based, mostly, on scaling arguments and Langevin theory.