Electronic and Magnetic Properties of Partially-Open Carbon Nanotubes

TL;DR

This study uses spin-polarized density functional theory to explore how the electronic and magnetic properties of partially-open carbon nanotubes can be tuned by structural modifications and external stimuli, revealing potential for nanoscale electronic and spintronic applications.

Contribution

It demonstrates that the electronic and magnetic properties of partially-open CNTs can be controlled by the degree of opening and external factors, introducing new possibilities for device engineering.

Findings

Partially-open CNTs can transition from metal to semiconductor to spin-polarized semiconductor.

Increasing the opening length stabilizes spin-polarized states over nonmagnetic states.

External electric fields and chemical modifications enable control over spin currents and half-metallicity.

Abstract

On the basis of the spin-polarized density functional theory calculations, we demonstrate that partially-open carbon nanotubes (CNTs) observed in recent experiments have rich electronic and magnetic properties which depend on the degree of the opening. A partially-open armchair CNT is converted from a metal to a semiconductor, and then to a spin-polarized semiconductor by increasing the length of the opening on the wall. Spin-polarized states become increasingly more stable than nonmagnetic states as the length of the opening is further increased. In addition, external electric fields or chemical modifications are usable to control the electronic and magnetic properties of the system. We show that half-metallicity may be achieved and the spin current may be controlled by external electric fields or by asymmetric functionalization of the edges of the opening. Our findings suggest that partially-open CNTs may offer unique opportunities for the future development of nanoscale electronics and spintronics.