Chirality Dependent Electronic and Spin Properties of SiC Nanotubes Calculated Using Relativistic Symmetrized Linearized Augmented Cylindrical Waves Method

Abstract

Abstract Spin and chirality dependent band structures of the single-walled (n1, n2) SiC nanotubes (NTs) with n1 = 7 and 7 ≥ n2 ≥ 0 are calculated using a first-principle cylindrical wave method. The helical and rotational symmetry of tubules was taken into account, the unit cells of any tubule being reduced to only two atoms that allowed to present the electronic structures of any tubule in a simple form with eight spin-dependent dispersion curves for the occupied states. All nanotubes are the wide-gap semiconductors with Eg between 2.26 and 3.15 eV and the spin-orbit splittings of the top of the valence and bottom of the conduction bandы lie in the range of 0.05–3.5 meV depending on chirality. The energies of the SO gaps in right- and left-handed NTs are exactly the same, but the spin directions are opposite. The chiral NTs most suitable for a selective spin transport with potentially high flows of the α- and β-electrons in opposite directions are noted.