Rotation Symmetry Spontaneous Breaking of Edge States in Zigzag Carbon Nanotubes

TL;DR

This paper analytically investigates edge states in zigzag carbon nanotubes, revealing that bond distortions can spontaneously break rotational symmetry, affecting electronic properties and potentially controllable by external fields.

Contribution

It provides analytical solutions showing spontaneous symmetry breaking of edge states due to bond distortions in zigzag carbon nanotubes, a novel insight into their electronic structure.

Findings

Edge states are mixed via bond distortion.

Asymmetric configurations have lower energy for certain N.

Symmetry breaking affects electronic state properties.

Abstract

Analytical solutions of the edge states were obtained for the (N, 0) type carbon nanotubes with distorted ending bonds. It was found that the edge states are mixed via the distortion. The total energies for N=5 and N>=7 are lower in the asymmetric configurations of ending bonds than those having axial rotation symmetry. Thereby the symmetry is breaking spontaneously. The results imply that the symmetry of electronic states at the apex depends on the occupation; the electron density pattern at the apex could change dramatically and could be controlled by applying an external field.