Computations on the cheap: Applications of kinetic Monte simulations to surface science problems

Abstract

In this talk, we will explore the use of a kinetic Monte Carlo (KMC) approach to surface science problems as diverse as silicon surface oxidation and etching, nucleation and growth of one-dimensional chains of group III metals upon adsorption on Si(100) surface, and temperature programmed desorption (TPD) of Fe-based surfaces during exposure to carbon monoxide. The computational tool of choice, KMC simulation, is relatively cheap to implement, and is appropriate to use for longer and bigger time and length scales than can be accessed using molecular dynamics simulations. However, these advantages come with a caveat when KMC modeling is not done with particular attention to detail, when its input parameters are not consistent with first-principles calculations as well as well-known experimental results, and more importantly, when all the surface processes are not accounted for – the lack of accuracy and exactness in the modeling may lead to questionable results and inaccurate predictions. These issues will be examined during the talk, along with additional technical challenges inherent in these kinds of studies, such as when an evolving surface system is dominated by extremely fast processes that effectively bring the simulations to a standstill.