Non-equilibrium GW approach to quantum transport in nano-scale contacts

TL;DR

This paper integrates the GW approximation into non-equilibrium quantum transport formalism to better understand correlation effects like the Kondo effect and applies it to molecular junctions, highlighting the importance of self-consistency.

Contribution

It introduces a GW-based method within the Keldysh formalism for non-equilibrium transport, demonstrating its effectiveness in modeling correlation effects in nano-scale contacts.

Findings

GW describes the Kondo effect and zero-temperature transport well.

Self-consistency is crucial for accurate current calculations.

Satellite structures in spectral functions are diminished with self-consistency.

Abstract

Correlation effects within the GW approximation have been incorporated into the Keldysh non-equilibrium transport formalism. We show that GW describes the Kondo effect and the zero-temperature transport properties of the Anderson model fairly well. Combining the GW scheme with density functional theory and a Wannier function basis set, we illustrate the impact of correlations by computing the I-V characteristics of a hydrogen molecule between two Pt chains. Our results indicate that self-consistency is fundamental for the calculated currents, but that it tends to wash out satellite structures in the spectral function.