TY - GEN

T1 - Scaled ensemble Monte Carlo

AU - Kriman, Alfred M.

AU - Joshi, Ravindra P.

PY - 1994

Y1 - 1994

N2 - We introduce a scaled ensemble Monte Carlo technique for the simulation of semiconductor plasmas at ultrashort times after excitation. The error, from counting statistics, can be decreased directly either by a computationally expensive increase in the number of simulation trajectories or by averaging over long times. The latter approach cannot be applied in studying ultrafast, far-from-equilibrium phenomena. The remaining alternative is to redistribute the computational effort to weight more heavily those regions with low densities. Scaled EMC uses ordinary EMC weighting, but simulates a different function, related by an energy- dependent scaling factor to the usual particle distribution. The simulation trajectories obey the same free-flight equations of motion as ordinary EMC, with no `splitting' of particles or iteration of trajectories. We describe simulations of modulation-doped GaAs structures under applied fields. G-, L- and X-valley carrier populations are determined across more than seven orders of magnitude in density, using only ten thousand simulation points, with fractionally small sampling error across a one-volt energy range. Using standard EMC with the same number of points, sampling statistics necessarily limits the range of simulable densities to less than four decades overall.

AB - We introduce a scaled ensemble Monte Carlo technique for the simulation of semiconductor plasmas at ultrashort times after excitation. The error, from counting statistics, can be decreased directly either by a computationally expensive increase in the number of simulation trajectories or by averaging over long times. The latter approach cannot be applied in studying ultrafast, far-from-equilibrium phenomena. The remaining alternative is to redistribute the computational effort to weight more heavily those regions with low densities. Scaled EMC uses ordinary EMC weighting, but simulates a different function, related by an energy- dependent scaling factor to the usual particle distribution. The simulation trajectories obey the same free-flight equations of motion as ordinary EMC, with no `splitting' of particles or iteration of trajectories. We describe simulations of modulation-doped GaAs structures under applied fields. G-, L- and X-valley carrier populations are determined across more than seven orders of magnitude in density, using only ten thousand simulation points, with fractionally small sampling error across a one-volt energy range. Using standard EMC with the same number of points, sampling statistics necessarily limits the range of simulable densities to less than four decades overall.

UR - http://www.scopus.com/inward/record.url?scp=0028735541&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:0028735541

SN - 0819414379

SN - 9780819414373

T3 - Proceedings of SPIE - The International Society for Optical Engineering

SP - 278

EP - 285

BT - Proceedings of SPIE - The International Society for Optical Engineering

A2 - Ferry, David K.

A2 - van Driel, Henry M.

Y2 - 27 January 1994 through 28 January 1994

ER -