Tunable Rashba spin splitting in quantum-spin Hall-insulator AsF bilayers
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- 作者：Jun Zhao ; Wanlin Guo ; Jing Ma
- 关键词：Rashba spin splitting ; topological insulator ; bilayer AsF ; tensile strain ; electric field
- 刊名：Nano Research
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：10
- 期：2
- 页码：491-502
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Nanotechnology; Materials Science, general; Atomic/Molecular Structure and Spectra; Condensed Matter Physics; Biotechnology; Biomedicine, general;
- 出版者：Tsinghua University Press
- ISSN：1998-0000
- 卷排序：10
文摘
Rashba spin splitting (RSS) in quantum-spin Hall (QSH) insulators is of special importance for fabricating spintronic devices. By changing the stacking order, a unique bilayered fluorinated arsenene (AsF) system is demonstrated to simultaneously possess RSS and non-trivial topological electronic states. We show by first-principle calculations that tunable RSS can be realized in bilayered AsF. Intrinsic RSS of 25 meV is obtained in the AA-stacked AsF bilayer by considering the spin-orbit coupling effect. The RSS can be tuned in the range of 0 to 50 meV by applying biaxial strains and can be significantly enhanced up to 186 meV in the presence of an external electric field. The AB-stacked AsF bilayer is shown to be a two-dimensional topological insulator with a sizable bulk bandgap of 140 meV (up to 240 meV), which originates from the spin-orbit coupling within the px,y–pz band inversion. Surprisingly, RSS up to 295 meV can be induced in the AB-stacked AsF bilayer by applying an external electric field, while the robust topology property without RSS can be retained under the applied strains. The AsF bilayers with tunable RSS and a nontrivial bandgap with AA- and AB-stacking orders can pave the way for designing spin field-effect transistors and new QSH devices.