School of Physics and State Key Laboratory of Crystal Materials, Shandong University , Jinan, Shandong 250100, China.
Nano Lett. 2015 Feb 11;15(2):1296-301. doi: 10.1021/nl504493d. Epub 2015 Jan 28.
Quantum spin Hall (QSH) effect is promising for achieving dissipationless transport devices but presently is achieved only at extremely low temperature. Searching for the large-gap QSH insulators with strong spin-orbit coupling (SOC) is the key to increase the operating temperature. We demonstrate theoretically that this can be solved in the chloridized gallium bismuthide (GaBiCl2) monolayer, which has nontrivial gaps of 0.95 eV at the Γ point, and 0.65 eV for bulk, as well as gapless edge states in the nanoribbon structures. The nontrivial gaps due to the band inversion and SOC are robust against external strain. The realization of the GaBiCl2 monolayer will be beneficial for achieving QSH effect and related applications at high temperatures.
量子自旋霍尔(QSH)效应有望实现无耗散输运器件，但目前仅在极低温度下实现。寻找具有强自旋轨道耦合(SOC)的大能隙 QSH 绝缘体是提高工作温度的关键。我们从理论上证明，这可以在氯化镓铋(GaBiCl2)单层中得到解决，该单层在 Γ 点具有非平凡的 0.95eV 能隙，体相的 0.65eV 能隙，以及纳米带结构中的无能隙边缘态。由于能带反转和 SOC 引起的非平凡能隙在外部应变下是稳定的。GaBiCl2 单层的实现将有利于在高温下实现 QSH 效应及相关应用。
