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arXiv · 2004.01244

Electron-Hole Asymmetry of Surface States in Topological Insulator Sb2Te3 Thin Films Revealed by Magneto-Infrared Spectroscopy

Yuxuan Jiang·Mahmoud M. Asmar·Xingyue Han·Mykhalo Ozerov·Dmitry Smirnov·Maryam Salehi·Seongshik Oh·Zhigang Jiang·Wang-Kong Tse·Liang Wu
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Abstract

When surface states (SSs) form in topological insulators (TIs), they inherit the properties of bulk bands, including the electron-hole (e-h) asymmetry but with much more profound impacts. Here, via combining magneto-infrared spectroscopy with theoretical analysis, we show that e-h asymmetry significantly modifies the SS electronic structures when interplaying with the quantum confinement effect. Compared to the case without e-h asymmetry, the SSs now bear not only a band asymmetry as that in the bulk but also a shift of the Dirac point relative to the bulk bands and a reduction of the hybridization gap up to 70%. Our results signify the importance of e-h asymmetry in band engineering of TIs in the thin film limit.

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Yuxuan Jiang, Mahmoud M. Asmar, Xingyue Han, Mykhalo Ozerov, Dmitry Smirnov, Maryam Salehi, Seongshik Oh, Zhigang Jiang, Wang-Kong Tse, Liang Wu. 2020-04-02. Electron-Hole Asymmetry of Surface States in Topological Insulator Sb2Te3 Thin Films Revealed by Magneto-Infrared Spectroscopy. https://doi.org/10.1021/acs.nanolett.0c01447

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