Persistent currents in carbon nanotubes

Abstract

Persistent currents driven by a static magnetic flux parallel to the carbon nanotube axis are investigated. Owing to the hexagonal symmetry of graphene the Fermi contour expected for a 2D lattice reduces to two points. However, the electron or hole doping shifts the Fermi energy upwards or downwards and, as a result, the shape of the Fermi surface changes. Such a hole doping leading to the Fermi level shift of (more or less) 1 eV has been recently observed experimentally. In this Letter we show that the shift of the Fermi energy changes dramatically the persistent currents and discuss the electronic structure and possible currents for zigzag as well as armchair nanotubes.