Functionalized Thallium Antimony Films as Excellent Candidates for Large-Gap Quantum Spin Hall Insulator
| Autor: | Zhang, Run-wu, Zhang, Chang-wen, Ji, Wei-xiao, Li, Sheng-shi, Yan, Shi-shen, Li, Ping, Wang, Pei-ji |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Sci. Rep., 6, 21351 (2016) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1038/srep21351 |
| Popis: | Group III-V films are of great importance for their potential application in spintronics and quantum computing. Search for two-dimensional III-V films with a nontrivial large-gap are quite crucial for the realization of dissipationless transport edge channels using quantum spin Hall (QSH) effects. Here we use first-principles calculations to predict a class of large-gap QSH insulators in functionalized TlSb monolayers (TlSbX2; (X = H, F, Cl, Br, I)), with sizable bulk gaps as large as 0.22~0.40 eV. The QSH state is identified by Z2 topological invariant together with helical edge states induced by spin-orbit coupling (SOC). Noticeably, the inverted band gap in the nontrivial states can be effectively tuned by the electric field and strain. Additionally, these films on BN substrate also maintain a nontrivial QSH state, which harbors a Dirac cone lying within the band gap. These findings may shed new light in future design and fabrication of QSH insulators based on two-dimensional honeycomb lattices in spintronics. Comment: 20 pages, 6 figures |
| Databáze: | arXiv |
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