Wang Dongchao, Chen Li, Liu Hongmei, Wang Xiaoli, Cui Guangliang, Zhang Pinhua, Zhao Dapeng, Ji Shuaihua
School of Physics, Shandong University, Shandong 250100, China.
Phys Chem Chem Phys. 2015 Feb 7;17(5):3577-83. doi: 10.1039/c4cp04502e.
Based on first-principles calculations, we systematically investigated the topological surface states of Bi and Sb thin films of 1-5 bilayers in (111) orientation without and with H(F) adsorption, respectively. We find that compared with clean Bi and Sb films, a huge band gap advantageous to observe the quantum spin Hall effect can be opened in chemically decorated bilayer Bi and Sb films, and the quantum phase transition from trivial (non-trivial) to non-trivial (trivial) phase is induced for a three bilayer Bi film and single (four) bilayer Sb film. Surface adsorption is an effective tool to manipulate the geometry, electronic structures and topological properties of film materials.
基于第一性原理计算，我们分别系统地研究了（111）取向的1 - 5个双层Bi和Sb薄膜在无H（F）吸附和有H（F）吸附情况下的拓扑表面态。我们发现，与清洁的Bi和Sb薄膜相比，化学修饰的双层Bi和Sb薄膜中可以打开有利于观察量子自旋霍尔效应的巨大带隙，并且对于三层双层Bi薄膜和单层（四层）双层Sb薄膜会诱导出从平凡（非平凡）到非平凡（平凡）相的量子相变。表面吸附是操纵薄膜材料的几何结构、电子结构和拓扑性质的有效工具。
