Prediction of two-dimensional topological insulator by forming a surface alloy on Au/Si(111) substrate
| Autor: | Shih-Yu Wu, Arun Bansil, C. C. Kuo, Christian P. Crisostomo, Zhi-Quan Huang, Hsin Lin, Chia-Hsiu Hsu, Wang-chi V. Yeh, Feng-Chuan Chuang, Hsin-Lei Chou |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Silicon Condensed matter physics Band gap chemistry.chemical_element 02 engineering and technology Electronic structure Substrate (electronics) 021001 nanoscience & nanotechnology 01 natural sciences law.invention chemistry Electron diffraction law Topological insulator 0103 physical sciences Monolayer Scanning tunneling microscope 010306 general physics 0210 nano-technology |
| Zdroj: | Physical Review B. 93 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | Two-dimensional (2D) topological insulators (TIs), which can be integrated into the modern silicon industry, are highly desirable for spintronics applications. Here, using first-principles electronic structure calculations, we show that the Au/Si(111)-$\sqrt{3}$ substrate can provide a platform for hosting 2D TIs obtained through the formation of surface alloys with a honeycomb pattern of adsorbed atoms. We systematically examined elements from groups III to VI of the periodic table at 2/3 monolayer coverage on Au/Si(111)-$\sqrt{3}$, and found that In, Tl, Ge, and Sn adsorbates result in topologically nontrivial phases with band gaps varying from 0 to 50 meV. Our scanning tunneling microscopy and low-energy electron diffraction experiments confirm the presence of the honeycomb pattern when Bi atoms are deposited on Au/Si(111)-$\sqrt{3}$, in accord with our theoretical predictions. Our findings pave the way for using surface alloys as a potential route for obtaining viable 2D TI platforms. |
| Databáze: | OpenAIRE |
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