The activation energies for the diffusion of small hetero-epitaxial islands, via the nucleation and motion of dislocations across the island, were calculated by using a Frenkel-Kontorova model. At so-called magic island sizes, the activation barriers for hetero-epitaxial island diffusion sharply decreased. Total energy calculations and molecular dynamics simulations, using the embedded atom method, confirmed the existence of a rapid diffusion process for 2-dimensional islands. One sign of the occurrence of this process was the detection of a strongly temperature dependent activation energy for diffusion.

J.C.Hamilton: Physical Review Letters, 1996, 77[5], 885-8