J.L. Blue, ACMD
We are modeling crystal growth by two commonly used methods, Molecular Beam Epitaxial Growth and Chemical Vapor Deposition. In both methods, atoms impinge on a crystalline substrate, are adsorbed, and are then can move around on the surface.
We are doing a Monte Carlo method to do the simulation. The key to rapid simulation is a search method we have developed to pick the right random item from a non-ordered list. A straight-forward method is , where N is the total number of items in the list. The formerly standard method was ; our method is . Last year Blue, Beichl, and Sullivan produced a method which is . This year I developed a method which is for most problems of interest. (If there are only L different probabilities or rates in the N items, the time is .)
Our first efforts use a simple model of the physics involved; this year I expect to simulate a real growth process, the deposition of chromium on an iron substrate, in collaboration with the Physics Laboratory.