Fluctuations of isolated and confined surface steps of monatomic height

Selke, W.
Institut für Theoretische Physik and JARA-HPC, RWTH Aachen University,
D-52056 Aachen, Germany


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--condensation (EC) are considered, both for isolated steps and 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 others, 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.