Electron transport in molecular devices

Abstract

The study of electronic transport in molecular devices is one of much research interest, with potential applications in a range of different fields. These devices have been experimentally constructed using many different techniques, and also modelled using several computational methods. The method most commonly used to perform such calculations is the non-equilibrium Green's function formalism combined with density functional theory (DFT). However, DFT calculations based on local exchange and correlation functionals contain self-interaction errors. The primary purpose of this work is to investigate the effects of these errors on electronic transport calculations. We describe the origin of the self-interaction error in DFT, as well as its consequences including the absence of the derivative discontinuity in approximate local exchange correlation potentials. Exact and approximate self-interaction corrections to remove these errors are also described.