ITR/AP: Simulation Tools for Open Quantum Systems with Application to Molecular Electronics Systems

North Carolina State University, Raleigh NC

Investigators

Abstract

This award was made on a 'small' category proposal submitted in response to the ITR solicitation, NSF-02-168. It supports computational and theoretical research and education to calculate current-voltage characteristics of molecular and nanoscale structures with an aim to understand and predict transport and other properties of these systems. The PIs will use a recently developed approach, based on the Keldysh nonequilibrium Green's function formalism combined with density-functional-theory-based simulations. Calculations will be performed using a newly developed real-space ab initio code. The main features of the code include: (i) fully atomistic treatment of the device electrodes which properly match the molecular device region; (ii) the correct self-consistent charge distribution generated under the effects of external bias and gate voltages, which includes the contributions from both the scattering and the bound states of the system; (iii) the implementation in an efficient numerical scheme for large-scale calculations on state-of-the art supercomputers. The PIs will extend this code in significant ways enabling calculations for multiprobe systems, current-induced forces, spin-dependent effects, and the dynamical response of molecular systems. The PIs aim to distribute codes developed in the course of the work to the broader materials research community. This award also supports education spanning the undergraduate, graduate, and postdoctoral level. Students and a postdoctoral research associate will be engaged in all aspects of the research projects. In addition, the PI aims to integrate part of the research into a series of simulation "short courses." %%% This award was made on a 'small' category proposal submitted in response to the ITR solicitation, NSF-02-168. It supports computational and theoretical research and education to calculate electron transport through molecular and nanoscale structures in response to an applied electric field with an aim to understand and predict the properties of these systems. The PIs will use a recently developed approach that combines a quantum many-body theory technique with electronic structure methods to create a tool that may be significant step towards realistically modeling electron transport through molecules and nanoscale structures. The PIs will develop new algorithms to extend the capabilities of existing code. The PIs aim to distribute codes developed in the course of the work to the broader materials research community. This research may have impact on the emerging fields of nanoelectronics and molecular electronics. This award also supports education spanning the undergraduate, graduate, and postdoctoral level. Students and a postdoctoral research associate will be engaged in all aspects of the research projects. In addition, the PI aims to integrate part of the research into a series of simulation "short courses." ***