Origin of Repulsive Interactions between Bunched Steps on Vicinal Solid Surfaces

Abstract

We investigate the origin of repulsive interactions between atomic steps on vicinal solid surfaces using a firstprinciples approach. Peculiar electronic states localized near step edges are found in (112n) nanofacets formed on the 4H-SiC(0001) vicinal surface. The localized states are gradually overlapped between the steps with shrinking the distance between atomic steps. From a viewpoint of energetics for (112n) nanofacets, the presence of the repulsive interaction between atomic steps is expected. We then suggest that the overlap between electrons distributed around step edges is a possible origin of the step-step repulsive interaction.