Many-body semiclassical approximation for semiconductor plasmas

Abstract

Realistic simulations of semiconductor plasmas require detailed, many-species descriptions of the phonon and electronic systems. Limited numerical power then usually requires simplifying approximations. One approximation is the use of a screened Coulomb interaction. When an accurate screening function is not available, or when a better electrostatics treatment is needed, one can perform ensemble Monte Carlo (EMC) simulations that use a phase-space- trajectories or 'molecular dynamics' (MD) evolution of the electronic ensemble. In these EMC/MD simulations, Coulomb scattering events are treated continuously in the MD evolution of electron trajectories rather than by instantaneous scattering in EMC. Dynamic scattering effects are then included accurately by the explicit correlated motion of the electron ensemble. The electron trajectories simulated by MD have until recently been completely classical. We describe extensions of EMC/MD into the semiclassical regime, thus incorporating quantum effects such as position-momentum uncertainty. The method takes account of the Fermi statistics of the many-electron ensemble, yielding spin-dependent exchange contributions to the forces and effective mass. We describe effects of these corrections on the velocity autocorrelation function and on thermalization of satellite-valley electrons.