Li Hangyu, Li Zhongyao
College of Science, University of Shanghai for Science and Technology, Shanghai 200093, People's Republic of China.
J Phys Condens Matter. 2023 Apr 6;35(25). doi: 10.1088/1361-648X/acc8ae.
The chloridized gallium bismuthide was predicted to be a two-dimensional topological insulator with large topological band gap. It may be beneficial for achieving the quantum spin Hall effect and its related applications at high temperatures. To better understand the quantum transport in topological nanoribbons, we investigated the effect of vacancy on the quantum transport of topological edge states in the armchair chloridized gallium bismuthide nanoribbons by combining density functional theory and nonequilibrium Green's function. The results suggest the vacancies at center are more likely to cause the scattering of topological edge states. The average scattering is insensitive to the enlargement of vacancy along the transport direction. More interestingly, the obvious scattering of topological edge states can only be found at some special energies, and these special energies are distributed quasi-periodically. The quasi-periodic scattering may be used as a kind of fingerprint of vacancies. Our studies may be helpful for the application of topological nanoribbons.
氯化镓铋被预测为具有大拓扑带隙的二维拓扑绝缘体。这可能有利于在高温下实现量子自旋霍尔效应及其相关应用。为了更好地理解拓扑纳米带中的量子输运，我们通过结合密度泛函理论和非平衡格林函数，研究了空位对扶手椅型氯化镓铋纳米带中拓扑边缘态量子输运的影响。结果表明，中心的空位更有可能导致拓扑边缘态的散射。平均散射对沿输运方向的空位扩大不敏感。更有趣的是，拓扑边缘态的明显散射只能在某些特殊能量处发现，并且这些特殊能量呈准周期性分布。这种准周期性散射可以用作空位的一种指纹。我们的研究可能有助于拓扑纳米带的应用。
