Orbital eigenchannel analysis for ab-initio quantum transport calculations

TL;DR

This paper presents a method to analyze the orbital contributions to quantum transport eigenchannels in nanoscopic conductors using first-principles calculations, illustrated with Ni nanocontacts.

Contribution

It introduces a technique to extract and analyze orbital contributions to transport eigenchannels from first-principles calculations, addressing challenges with non-orthogonal basis sets.

Findings

Orbital nature of eigenchannels in Ni nanocontacts elucidated.

Method handles non-orthogonal basis sets and first-principles Hamiltonians.

Provides insights into quantum transport at the orbital level.

Abstract

We show how to extract the orbital contribution to the transport eigenchannels from a first-principles quantum transport calculation in a nanoscopic conductor. This is achieved by calculating and diagonalizing the first-principles transmission matrix reduced to selected scattering cross-sections. As an example, the orbital nature of the eigenchannels in the case of Ni nanocontacts is explored, stressing the difficulties inherent to the use of non-orthogonal basis sets and first-principles Hamiltonians.