Spin transport in disordered single-wall carbon nanotubes contacted to ferromagnetic leads

TL;DR

This paper investigates spin-dependent electron transport in disordered and clean carbon nanotubes connected to ferromagnetic contacts, providing insights into giant magnetoresistance effects in these nanostructures.

Contribution

It offers a theoretical analysis of spin transport in both disordered and disorder-free CNTs with ferromagnetic contacts, highlighting the impact of disorder and contact effects.

Findings

Disorder influences spin transport properties significantly.

Giant magnetoresistance effects are observed in the studied CNTs.

Long CNTs up to several hundred nanometers are feasible for spin transport studies.

Abstract

Recent conductance measurements on multi-wall carbon nanotubes (CNTs) reveal an effective behavior similar to disordered single-wall CNTs. This is due to the fact that electric current flows essentially through the outermost shell and is strongly influenced by inhomogeneous electrostatic potential coming from the inner tubes. Here, we present theoretical studies of spin-dependent transport through disorder-free double-wall CNTs as well as single-wall CNTs with Anderson-type disorder. The CNTs are end-contacted to ferromagnetic electrodes modelled as fcc (111) surfaces. Our results shed additional light on the giant magnetoresistance effect in CNTs. Some reported results concern realistically long CNTs, up to several hundred nanometers.