Density functional theory based many-body analysis of electron transport through molecules

Abstract

We present a method which uses density functional theory (DFT) to treat transport through a single molecule connected to two conducting leads for the weak and intermediate coupling. This case is not accessible to standard nonequilibrium Green's function calculations. Our method is based on a mapping of the Hamiltonian on the molecule to a limited set of many-body eigenstates. This generates a many-body Hamiltonian with parameters obtained from ground-state local (spin) density approximation-DFT calculations. We then calculate the transport using many-body Green's function theory. We compare our results with existing density matrix renormalization group calculations for spinless and for spin-1/2 fermion chains and find good agreement.