论文标题
拓扑BI/BISB异质结构中的波功能和表面状态的远程渗透
Long-range permeation of wave function and superficial surface state due to strong quantum size effects in topological Bi/BiSb heterojunctions
论文作者
论文摘要
量子尺寸效应对电子具有重大影响，因此它甚至可以改变其受拓扑保护的特性。这种现象的一个例子是在有限的厚度拓扑 - 绝缘膜中，拓扑保护的无间隙表面状态的间隙开口。然而，关于拓扑异质结的量子大小效应尚不了解。在这项研究中，通过根据著名的Liu-Allen模型来计算BI/BI $ _ {1-X} $ sb $ _ {X} $的单粒子光谱，我们发现拓扑异质结中的强量子大小效应会产生出乎意料的频段一致性。波的功能通过附着的材料互相渗透，即使在80 nm厚的异质结中也会发生。此外，我们从理论上发现，从BI表面获得的两个主要光谱之一并不代表BI的真实表面状态。这一发现可能推翻了对BI拓扑表面状态的先前理解。
The quantum size effect has a significant impact on electrons, such that it can even change their topologically protected properties. An example of this phenomenon is the gap opening in the topologically protected gapless surface state in finite-thickness topological-insulator films. However, much is not known about the quantum size effect in topological heterojunctions. In this study, by calculating the single-particle spectrum of Bi/Bi$_{1-x}$Sb$_{x}$ based on the well-known Liu-Allen model, we found that the strong quantum size effect in topological heterojunctions yields an unexpected band alignment. The wave functions permeate each other through the attached materials, and this occurs even in 80-nm-thick heterojunctions. Furthermore, we theoretically found that one of the two major spectra obtained from the Bi surface does not represent the true surface state of Bi. This finding may overturn the previous understanding of the topological surface state of Bi.
