Supersymmetry in carbon nanotubes in a transverse magnetic field

TL;DR

This paper investigates how a transverse magnetic field affects the electronic properties of carbon nanotubes, revealing supersymmetry that stabilizes metallic states and alters energy gaps and density of states.

Contribution

It introduces a supersymmetric model for electrons in carbon nanotubes under a transverse magnetic field, showing how this symmetry influences their electronic properties.

Findings

Supersymmetry protects low energy states and stabilizes metallic behavior.

Fermi velocity is suppressed at half-filling in metallic tubes.

Energy gaps are reduced in semiconducting tubes.

Abstract

Electron properties of Carbon nanotubes in a transverse magnetic field are studied using a model of a massless Dirac particle on a cylinder. The problem possesses supersymmetry which protects low energy states and ensures stability of the metallic behavior in arbitrarily large fields. In metallic tubes we find suppression of the Fermi velocity at half-filling and enhancement of the density of states. In semiconducting tubes the energy gap is suppressed. These features qualitatively persist (although to a smaller degree) in the presence of electron interactions. The possibilities of experimental observation of these effects are discussed.