Two-dimensional elastic lattice model with spontaneous stress - art.no. 045422

A two-dimensional elastic lattice model with spontaneous stress is numerica lly simulated and compared with the continuum elasticity theory. Two adatom s separated by a distance x interact repulsively with an x(-2) potential in agreement with continuum theory, but the strength of the interaction is ab out half of the theoretical prediction due to the relaxation of the adatom position as well as substrate atoms. Repulsive interaction between two step edges of the same sign is also proportional to x-2, but with a coupling st rength much larger than the continuum elasticity, because forces are distri buted not on a single plane but on two layers. The same reason leads to a g reat discrepancy in the interaction between steps with the opposite signs. Even though the continuum elasticity predicts no interaction, they seem to interact repulsively with the same x(-2) dependence. Between step edges on the groove, the interaction is apparently long-ranged, proportional to x(-1 .5).