Implementation of non-equilibrium vertex corrections in KKR: transport through disordered layers

TL;DR

This paper extends ab initio quantum transport theory to disordered systems by implementing non-equilibrium vertex corrections within the KKR method, demonstrating their importance through alloy layer calculations.

Contribution

The paper introduces a new implementation of non-equilibrium vertex corrections in the KKR scheme for disordered systems, enhancing the accuracy of quantum transport calculations.

Findings

Vertex corrections significantly affect transport properties in disordered alloys.

Comparison with supercell calculations validates the implementation.

The method is applicable to complex nanoelectronic devices with disorder.

Abstract

The theoretical description of modern nanoelectronic devices requires a quantum mechanical treatment and often involves disorder, e.g. form alloys. Therefore, the ab initio theory of transport using non-equilibrium Green's functions is extended to the case of disorder described by the coherent potential approximation. This requires the calculation of non-equilibrium vertex corrections. We implement the vertex corrections in a Korringa-Kohn-Rostoker multiple scattering scheme. In order to verify our implementation and to demonstrate the accuracy and applicability we investigate a system of an iron-cobalt alloy layer embedded in copper. The results obtained with the coherent potential approximation are compared to supercell calculations. It turns out that vertex corrections play an important role for this system.