Self-organization of clusters by a standing surface acoustic wave

The diffusion of clusters on a crystalline substrate submitted to a standing surface acoustic wave (StSAW) is studied using molecular dynamics simulations. The distributions of positions of clusters with two, three, and four atoms are calculated and evidence that the wave encourages the presence of the clusters in the vicinity of the maximum transverse displacement field of the substrate. The physical mechanism leading to this self-organization is expected to be equivalent to the one operating for a single adatom, i.e., the displacement of the clusters induced by the longitudinal displacement field of the wave. The detailed shapes of the distributions of positions of clusters are related to the different clusters’ orientation and configurations. Finally, the possibility to use a StSAW to self-organize nanostructures during growth is addressed by simulating a deposition process on the substrate. We evidence that the use of a StSAW allows to especially control the spatial repartition of grown nanostructures.