Spin Properties of Chiral SiC Nanotubes

The band structure of single-walled SiC (n₁, n₂) nanotubes (n₁ = 7, 0 ≤ n₂ ≤ 7) as a function of spin and chirality has been calculated by the relativistic augmented cylindrical wave method. It has been found that the nanotubes are wide-band semiconductors with E_g ranging from 2.26 to 3.15 eV, and the spin–orbit splitting of the valence and conduction band edges are in the range 0.05–3.5 meV. The spin–orbit gap energies in righthanded and lefthanded enantiomers coincide, but the spins are opposite. Chiral nanotubes most suitable for selective spin transport with potentially high fluxes of α- and β-electrons in opposite directions have been determined.