Topologically induced surface electron state on Si(111) surfaces

SURFACE SCIENCE

卷:602

Article

Takagi, Yoshiteru^1,2,3  Okada, Susumu^1,2,3 

[1] Univ Tsukuba, Grad Sch Pure & Appl Sci, Tsukuba, Ibaraki 3058571, Japan

[2] Univ Tsukuba, Ctr Computat Sci, Tsukuba, Ibaraki 3058571, Japan

[3] Japan Sci & Technol Agcy, CREST, Saitama 3320012, Japan

关键词: edge state;    surface state;    density functional calculations;   

DOI  :  10.1016/j.susc.2008.07.017

来源: Elsevier

【 摘 要 】

First-principle electronic structure calculation reveals the appearance of a new class of surface state on hydrogenated and clean Si(111) surfaces. The states are found to exhibit different characteristics to conventional surface electron states in terms of the peculiar distribution of the wavefunction depending on the wavenumber. In addition, the state results in flat dispersion bands in a part of the surface Brillouin zone having energy of about 8 eV below the top of the valence band. An analytic expression based on the tight-binding approximation corroborates the surface electron state results from the delicate balance of the electron transfer among the atoms situated near the surface. The obtained results give a possible extension and generalization of the edge state in graphite ribbons with zigzag edges. (C) 2008 Elsevier B.V. All rights reserved.

【 授权许可】

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