Dresden 2006 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HL: Halbleiterphysik

HL 9: Poster I

HL 9.59: Poster

Montag, 27. März 2006, 15:15–17:45, P3

Parallel implementation of the recursive Green’s function method — •Panagiotis Drouvelis^1,2, Peter Schmelcher^1,3, and Peter Bastian² — ¹Theoretische Chemie, Universität Heidelberg, Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany — ²Interdisziplin'ares Zentrum für Wissenschaftliches Rechnen, Im Neuenheimer Feld 368, D-69120 Heidelberg, Germany — ³Physikalisches Institut, Philosophenweg 12, Universität Heidelberg, D-69120 Heidelberg, Germany

A parallel algorithm for the implementation of the recursive Green’s function technique, which is extensively applied in the coherent scattering formalism, will be presented. The algorithm performs a domain decomposition of the scattering region among the processors participating in the computation and calculates the Schur’s complement block in the form of distributed blocks among the processors. If the method is applied recursively, thereby eliminating the processors cyclically, it is possible to arrive at a Schur’s complement block of small size and compute the desired block of the Green’s function matrix directly. The numerical complexity due to the longitudinal dimension of the scatterer scales linearly with the number of processors, though, the computational cost due to the processors’ cyclic reduction, establishes a bottleneck to achieve efficiency 100%. The proposed algorithm is accompanied by a performance analysis for two numerical benchmarks, in which the dominant sources of computational load and parallel overhead as well as their competitive role in the efficiency of the algorithm will be demonstrated.