Elastic Interactions in Molecular Beam Epitaxy

Molecular Beam Epitaxy (MBE) is a widely used technique in industry and research alike to manufacture objects with tailor made details on length scale of the order of an Angstrom. It consists of a beam of atoms or molecules showering down on an initially flat surface, the substrate. Experimental results [38,50] show that this process can be used to form Quantum Dots. It has been suggested [50] that the growth process is dominated by elastic long-range interactions through the substrate.

This project will concern itself with the computational simulation of the elastic interaction between adatoms using a repulsive potential [36] and a generalization of the Monte-Carlo approach developed previously [18]. We can effectively introduce the atomic details of specific materials and perform a simulation that closely reproduces the real system.

The simulation of this system will allow us to elucidate how the microscopic dynamics induced by the elastic strain lead to the results observed experimentally [38,50] such as the island size distribution and inter-island spacing, leading to the formation of Quantum Dots. It will also enable us to complement the understanding obtained from the experiments by showing us the early stages of island nucleation and growth that continue to elude experimental observation. In that, simulation allows us to test the importance of the role played by the elastic strain.

© Copyright 2004 Bruno Goncalves - All rights reserved