Transport properties of molecular junctions from many-body perturbation theory

TL;DR

This paper investigates the conductance of single molecule junctions using many-body perturbation theory, showing that including non-diagonal self-energy elements in wavefunctions improves agreement with experimental results.

Contribution

It demonstrates that updating wavefunctions with non-diagonal self-energy elements is essential for accurate conductance predictions in molecular junctions.

Findings

Correcting eigenvalues alone does not significantly change conductance.

Including non-diagonal self-energy elements reduces conductance and aligns better with experiments.

Standard quasiparticle corrections are insufficient without wavefunction updates.

Abstract

The conductance of single molecule junctions is calculated using a Landauer approach combined to many-body perturbation theory MBPT) to account for electron correlation. The mere correction of the density-functional theory eigenvalues, which is the standard procedure for quasiparticle calculations within MBPT, is found not to affect noticeably the zero-bias conductance. To reduce it and so improve the agreement with the experiments, the wavefunctions also need to be updated by including the non-diagonal elements of the self-energy operator.