Magnetoelectronic states of carbon toroids

Abstract

Magnetoelectronic states of carbon toroids have been studied within the tight-binding model. These states are mainly determined by the magnitude and the direction of the magnetic field, and the toroid geometry (chiral angle, height, and radius). The magnetic field can make the angular momentum ( L) along the longitudinal direction undergo both a large shift and strong coupling. This effect leads to the destruction of state degeneracy, the change of energy spacing, the alternation of quantization of wave function, the vanishing of periodic Aharonov–Bohm oscillations, and the semiconductor–metal transition (SMT). Armchair carbon toroids are quite different from zigzag carbon toroids in features such as state degeneracy, energy gap, existence of the SMT, and dependence on the magnetic field.