The electronic structure and magnetic properties of the chiral toroidal carbon nanotubes

Based on the tight-binding model of pi electrons for a graphite sheet, the electronic structure of the chiral toroidal carbon nanotubes (TCNTs) has be en derived. The quantum properties and magnetic pattern of TCNTs have been investigated in detail in this paper. A magnetic field can induce a metal-s emiconductor transition for type I and II TCNTs. The computation and analys is also show: when T = OK, the magnetism of type I and 11 TCNTs are a linea rly function of the magnetic flux Phi, with a period Phi (0), ( h/e), which is sensitive to chiral angle theta, toroidal width r and temperture T, ind ependent of toroidal radius R. The magnetism of chiral TCNTs is much strong er than that of the armchair or zigzag TCNTs. The magnetism of type m TCNTs is very weak, without regularity.