In this talk I will review previous work on weakly off-lattice KMC simulation of quantum dots, including recent progress on a two-scale domain decomposition approach. This method is used to study various phenomena that take place during heteroepitaxial growth. For example, it is demonstrated that faceted quantum dots occur via the layer-by-layer nucleation of pre-pyramids on top of a critical layer with faceting occurring by anisotropic surface diffusion.
It is also shown that the dot growth is enhanced by the depletion of the critical layer which leaves behind a wetting layer. Capping simulations provide insight into the mechanisms behind dot erosion and ring formation.
I will then discuss efforts to extend these methods to fully off-lattice simulations. This is joint work with Peter Smereka and Henry Boateng.