DFT-based many-body analysis of electron transport through molecules

TL;DR

This paper introduces a DFT-based many-body approach for electron transport through molecules, extending analysis to weak and intermediate coupling regimes inaccessible to standard methods.

Contribution

It develops a novel method combining DFT and many-body Green's functions to analyze molecular transport beyond traditional NEGF limitations.

Findings

Good agreement with DMRG calculations for spinless and spin-1/2 chains.

Applicable to weak and intermediate coupling regimes.

Provides a new tool for molecular electron transport analysis.

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 non-equilibrium Green's function (NEGF) 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 L(S)DA-DFT calculations. We then calculate the transport using many-body Green's function theory. We compare our results with existing density matrix renormalization group (DMRG) calculations for spinless and for spin-1/2 fermion chains and find good agreement.