Series of (n×2) Si-rich reconstructions of β-SiC(001): A prospective atomic wire

摘要: We perform ab initio plane wave supercell density functional calculations on three candidate models of the (3 x 2) reconstruction beta-SiC(001) surface. find that two-adlayer asymmetric-dimer model (TAADM) is unambiguously favored for all reasonable values Si chemical potential. then use structures derived from TAADM parent to silicon lines are observed when annealed (the (n series reconstructions), using a tight-binding method. as we increase n, and so separate lines, structural transition occurs in which top addimer line flattens. also associated with separation large decrease HOMO-LUMO gap, HOMO state becomes quasi-one-dimensional. These properties qualititatively quantitatively different electronic original reconstruction.