Computational Challenges in Nanoscale Device Modeling
E. Polizzi, A. Sameh and H. Sun
Purdue University, US
Keywords: nanoscale devices, Green's function, NEGF-Poisson, parallel numerical algorithms, linear systems, generalized eigenvalue problems
The development of new simulation tools is critical for the exploration of quantum transport in nanoscale devices. Such simulation is commonly performed by solving self-consistently the transport problem using The Non-Equilibrium Green's Functions (NEGF) formalism and the Poisson's equation to account for the space charge effects. The quest for ever higher levels of detail and realism in such simulations as the modeling of multidimensional devices with detailed band structure calculations with (or without) the inclusion of scattering effects, requires huge computational effort. Hence, the need for an active research effort in developing novel numerical techniques and parallel algorithms that are ideally suited for high-end computing platforms. In this paper, we will present new efficient parallel schemes for computing the Green's function in the transport problem. We will describe a novel parallel algorithm for solving the large number of linear algebraic systems involved in the Green function calculations over all energy levels of the system. A novel parallel solver for obtaining the smallest eigenpairs of those symmetric generalized eigenvalue problems that arise when considering the subbands decomposition approach of the transport problem is also described in detail.
Nanotech 2004 Conference Technical Program Abstract