Parallelization of the Nanoelectronic Modeling Tool (NEMO 1-D) on a Beowulf Cluster

NEMO’s main task is the computation of current-voltage (I-V) characteristics for resonant tunneling diodes (RTDs). The primary model for high performance RTDs is the full band sp3s∗ tight binding simulation, which is based on a numerical double integral of energy and transverse momentum over a transport kernel at each bias point. A full charge self-consistent simulation invoking this model on a single CPU is prohibitively expensive, as the generation of a single I-V curve would take about 1–2 weeks to compute. Simplified charge self-consistent models, eliminating the numerical momentum integral for the quantum mechanical charge self-consistency, followed by a single pass double integration for the current, have been used in the past. However, Computation on a parallel computer now enables the thorough exploration of quantum mechanical transport including charge self-consistency effects within the entire Brillouin zone based on the double integral. Various parallelization schemes (fine, coarse, and mixed) are presented and evaluated in their performance. Finally a comparison to experimental data is given.