title: Band gap engineering of silicene zigzag nanoribbons with perpendicular electric fields: a theoretical study.
abstract: The electronic properties of silicene zigzag nanoribbons with the presence of perpendicular fields are studied by using first-principles calculations and the generalized nearest neighboring approximation method. In contrast to the planar graphene, in silicene the Si atoms are not coplanar. As a result, by applying perpendicular fields to the two-dimensional silicene sheet, the on-site energy can be modulated and the band gap at the Dirac point is open. The buckled structure also creates a height difference between the two edges of the silicene zigzag nanoribbons. We find that the external fields can modulate the energies of spin-polarized edge states and their corresponding band gaps. Due to the polarization in the plane, the modulation effect is width dependent and becomes much more significant for narrow ribbons.
authors.affiliation: Institute for Materials Research, Tohoku University, Aobaku, Sendai 980-8577, Japan. liangyy@imr.tohoku.ac.jp
authors.forename: Yunye
authors.initials: Y
authors.lastname: Liang
authors.forename: Vei
authors.initials: V
authors.lastname: Wang
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizuseki
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kawazoe