Ensemble Monte Carlo and Full-Wave Electrodynamic Models Implemented Self-Consistently on a Parallel Processor Using Perfectly Matched Layer Boundary Conditions

We have been using a self-consistent formulation of full-wave electromagnetic solvers andensemble Monte Carlo techniques to model ultrafast photoconductivity. Our simulationsare running on a MasPar machine. This paper will address aspects ofthis simulation whichmay interest workers who are simulating not only photoconductive systems but othersystems as well which involve electrodynamics, waves and wave phenomena and ensembleMonte Carlo transport models. In particular, we will report on the inclusion of perfectlymatched layer approaches to absorbing boundary conditions for electromagnetic waves.These have in the past several years become widely used in computational electromagneticscodes because they reduce error due to spurious numerical wave reflection off ofan absorbing boundary by several orders of magnitude. We will also address the issue ofcomputational cost and show that a full-wave electromagnetic approach is morecompetitive with a Poisson's equation approach than one might believe. Lastly, oursystem has the feature that the active portion where the electrons and holes lie is in fact asmall fraction of the total experimental system's volume. Unless care is exerted one eitherhas a very significant load imbalance problem or high communications overhead. Wecompare two different tradeoffs between load imbalance and communications overhead