Fast Computational Methods for Computing Quantum Transport in Nanowires and Nanotubes

摘要

Nanowires and nanotubes are promising building blocks for designing nanoscale devices for sensing warfare agents. Computer models are key to designing and improving such sensors. Due to their nanoscale size, quantum models are needed to model the transport of electrons in this type of device. Few methods exist to accurately calculate quantum transport for systems comprising hundreds of thousands of atoms. The approach we are taking is based on the non equilibrium Green's function approach 1, 2, 3) (NEGF) and is an exact order N method to calculate the charge density and the IV characteristic of a device. We are presenting a novel numerical technique which allows computing in parallel the Green's function. The computational cost scales linearly with the number atoms and the parallel efficiency on benchmarks problems is nearly optimal. Based on our benchmarks results this method will enable modeling devices of unprecedented size.