Contact-induced spin polarization in carbon nanotubes

TL;DR

This paper explores how contacting carbon nanotubes with a magnetic substrate can induce spin polarization, providing theoretical formulas and models to estimate the magnitude and stability of the resulting magnetic moments.

Contribution

It introduces a theoretical framework and models to analyze contact-induced spin polarization in carbon nanotubes, highlighting conditions for significant magnetic moments.

Findings

Significant magnetic moments can be induced in carbon nanotubes.

Derived formulas describe charge transfer and energy costs.

Estimated stability of induced spin polarization.

Abstract

Motivated by the possibility of combining spintronics with molecular structures, we investigate the conditions for the appearance of spin-polarization in low-dimensional tubular systems by contacting them to a magnetic substrate. We derive a set of general expressions describing the charge transfer between the tube and the substrate and the relative energy costs. The mean-field solution of the general expressions provides an insightful formula for the induced spin-polarization. Using a tight-binding model for the electronic structure we are able to estimate the magnitude and the stability of the induced moment. This indicates that a significant magnetic moment in carbon nanotubes can be observed.