Breaking of Nanotube Symmetry by Substrate Polarization

TL;DR

This paper investigates how substrate and nanotube polarization can significantly alter the electronic bandstructure of nanotubes, breaking symmetry and lifting degeneracy, with potential implications for nanotube-based electronic devices.

Contribution

It introduces a linear approximation model to study the effect of substrate polarization on nanotube bandstructure, highlighting the impact of work function differences.

Findings

Work function difference can break band symmetry.

Subband splitting of about 50 meV in [10,10] nanotube.

Polarization effects qualitatively change nanotube electronic properties.

Abstract

Substrate and nanotube polarization are shown to change qualitatively a nanotube bandstructure. The effect is studied in a linear approximation in an external potential which causes the changes. A work function difference between the nanotube and gold surface is estimated to be large enough to break the band symmetry and lift a degeneracy of a lowest but one subband of a metallic nanotube. This subband splitting for [10,10] nanotube is about 50 meV in absence of other external potential.