A wave function based ab initio non-equilibrium Green's function approach to charge transport

TL;DR

This paper introduces a wave function based ab initio non-equilibrium Green's function method for calculating charge transport in molecular junctions, incorporating two-particle effects and matching experimental current magnitudes.

Contribution

It presents a novel wave function based ab initio approach combined with a tight binding approximation within the Keldysh formalism, including two-particle effects for the first time.

Findings

Two-particle effects contribute about 5% to the current.

Calculated current magnitudes are consistent with experimental data.

The method effectively models the full current-voltage characteristics.

Abstract

We present a novel ab initio non-equilibrium approach to calculate the current across a molecular junction. The method rests on a wave function based description of the central region of the junction combined with a tight binding approximation for the electrodes in the frame of the Keldysh Green's function formalism. In addition we present an extension so as to include effects of the two-particle propagator. Our procedure is demonstrated for a dithiolbenzene molecule between silver electrodes. The full current-voltage characteristic is calculated. Specific conclusions for the contribution of correlation and two-particle effects are derived. The latter are found to contribute about 5% to the current. The order of magnitude of the current coincides with experiments.