Intrinsic Spin-Orbit Coupling in Zigzag and Armchair Graphene Nanoribbons

Starting from a tight-binding model, we derive the energy gaps induced by intrinsic spin-orbit (ISO) coupling in the low-energy band structures of graphene nanoribbons. The armchair graphene nanoribbons may be either semiconducting or metallic, depending on their widths in the absence of ISO interac...

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Bibliographic Details
Main Authors: Ying Li, Erhu Zhang, Baihua Gong, Shengli Zhang
Format: Article
Language:English
Published: Hindawi Limited 2011-01-01
Series:Journal of Nanomaterials
Online Access:http://dx.doi.org/10.1155/2011/364897
Description
Summary:Starting from a tight-binding model, we derive the energy gaps induced by intrinsic spin-orbit (ISO) coupling in the low-energy band structures of graphene nanoribbons. The armchair graphene nanoribbons may be either semiconducting or metallic, depending on their widths in the absence of ISO interactions. For the metallic ones, the gaps induced by ISO coupling decrease with increasing ribbon widths. For the ISO interactions, we find that zigzag graphene nanoribbons with odd chains still have no band gaps while those with even chains have gaps with a monotonic decreasing dependence on the widths. First-principles calculations have also been carried out, verifying the results of the tight-binding approximation. Our paper reveals that the ISO interaction of graphene nanoribbons is governed by their geometrical parameters.
ISSN:1687-4110
1687-4129