Persistent currents in finite zigzag carbon nanotubes

Magnetic properties of finite zigzag carbon nanotubes are studied within the tight-binding model. The spin– B interaction (Zeeman splitting) causes the metal–semiconductor transition and thus produces a large persistent current ( J) with special jump structures. This effect makes all zigzag carbon nanotubes exhibit a gigantic paramagnetism. It also destroys the periodicity of magnetic properties. The dependence on the magnetic flux, the length ( w), the radius ( r), the temperature ( T), and the chirality (zigzag or armchair) is strong. The amplitude of J quickly decreases with increasing of ( w, r, T). Zigzag carbon nanotubes differ significantly from armchair carbon nanotubes (or infinite zigzag carbon nanotubes) in features such as magnetic susceptibility and in special structures in J.