Topological Surface State Evolution in Bi$_2$Se$_3$ via Surface Etching
| Autor: | Yue, Ziqin, Huang, Jianwei, Wang, Ruohan, Li, Jia-Wan, Rong, Hongtao, Guo, Yucheng, Wu, Han, Zhang, Yichen, Kono, Junichiro, Zhou, Xingjiang, Hou, Yusheng, Wu, Ruqian, Yi, Ming |
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| Rok vydání: | 2024 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Topological insulators are materials with an insulating bulk interior while maintaining gapless boundary states against back scattering. Bi$_2$Se$_3$ is a prototypical topological insulator with a Dirac-cone surface state around $\Gamma$. Here, we present a controlled methodology to gradually remove Se atoms from the surface Se-Bi-Se-Bi-Se quintuple layers, eventually forming bilayer-Bi on top of the quintuple bulk. Our method allows us to track the topological surface state and confirm its robustness throughout the surface modification. Importantly, we report a relocation of the topological Dirac cone in both real space and momentum space, as the top surface layer transitions from quintuple Se-Bi-Se-Bi-Se to bilayer-Bi. Additionally, charge transfer among different surface layers is identified. Our study provides a precise method to manipulate surface configurations, allowing for the fine-tuning of the topological surface states in Bi$_2$Se$_3$, which represents a significant advancement towards nano-engineering of topological states. Comment: 21 pages, 5 figures, accepted for publication in Nano Letters |
| Databáze: | arXiv |
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