Electronic structure of spheroidal fullerenes

TL;DR

This paper investigates how slight spheroidal deformation affects the electronic structure of fullerenes, revealing a fine energy spectrum structure and sensitivity to magnetic field orientation.

Contribution

It introduces a field-theory model using a Dirac equation on spheroids to analyze electronic states in deformed fullerenes, highlighting the effects of small shape deformations and magnetic fields.

Findings

Deformation causes a fine structure in the electronic energy spectrum.

Magnetic field orientation significantly influences energy level splitting.

The first electronic level remains unaffected by magnetic field in the x direction.

Abstract

Graphite is an example of a layered material that can be bent to form fullerenes which promise important applications in electronic nanodevices. The spheroidal geometry of a slightly elliptically deformed sphere was used as a possible approach to fullerenes. We assumed that for a small deformation the eccentricity of the spheroid is much more smaller then one. We are interested in the elliptically deformed fullerenes C70 as well as in C60 and its spherical generalizations like big C240 and C540 molecules. In the next study the expanded field-theory model was proposed to study the electronic states near the Fermi energy in spheroidal fullerenes. The low energy electronic wave functions obey a two-dimensional Dirac equation on a spheroid with two kinds of gauge fluxes taken into account. We shown exactly how a small deformation of spherical fullerenes provokes an appearance of fine structure in the electronic energy spectrum as compared to the spherical case. The effect of a weak uniform magnetic field on the electronic structure of slightly deformed fullerene molecules was also studied. We shown that the fine structure of the electronic energy spectrum is very sensitive to the orientation of the magnetic field. We found that the magnetic field pointed in the x direction does not influence the first electronic level whereas it causes a splitting of the second energy level.