First-principles phase-coherent transport in metallic nanotubes with realistic contacts

TL;DR

This paper uses first-principles calculations to analyze phase-coherent electron transport in metallic carbon nanotubes with realistic contacts, comparing different metals and contact geometries to predict contact quality.

Contribution

It provides the first quantitative ab-initio predictions of contact transparency and transport properties for metallic CNTs with realistic contacts.

Findings

Ti forms the best contact among the metals studied.

Al and Au make poor contacts.

Contact geometry influences transport properties.

Abstract

We present first-principles calculations of phase coherent electron transport in a carbon nanotube (CNT) with realistic contacts. We focus on the zero-bias response of open metallic CNT's considering two archetypal contact geometries (end and side) and three commonly used metals as electrodes (Al, Au, and Ti). Our ab-initio electrical transport calculations make, for the first time, quantitative predictions on the contact transparency and the transport properties of finite metallic CNT's. Al and Au turn out to make poor contacts while Ti is the best option of the three. Additional information on the CNT band mixing at the contacts is also obtained.