Aryal Niraj, Manousakis Efstratios
Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306-4350, United States of America.
J Phys Condens Matter. 2020 May 27;32(23):235001. doi: 10.1088/1361-648X/ab70c2.
We study the topological states which appear at the interface between a topological insulator (TI) and a conventional insulator (CI) using effective Hamiltonians which accurately describe the band structure of the BiSe family. Due to the hybridization between the TI and the CI states, the band-gap that appears in the interface Dirac cone decreases and ultimately vanishes by tuning the interface-hopping amplitude or by selecting a CI of appropriate band effective mass. More importantly, we find that a topologically trivial TI slab can be made non-trivial and vice-versa by tuning of such an interface-hopping amplitude or by tuning the CI band effective-mass; namely, a topological phase transition can be induced in such heterostructures indicated by the presence or absence of gapless linear edge modes. We discuss the relevance and realization of our results and conclusions in future experiments.
我们使用能准确描述BiSe族能带结构的有效哈密顿量，研究了拓扑绝缘体（TI）与传统绝缘体（CI）界面处出现的拓扑态。由于TI态与CI态之间的杂化，通过调节界面跳跃幅度或选择具有合适能带有效质量的CI，界面狄拉克锥中出现的带隙会减小并最终消失。更重要的是，我们发现通过调节这种界面跳跃幅度或调节CI能带有效质量，可以使拓扑平凡的TI平板变为非平凡的，反之亦然；也就是说，通过无隙线性边缘模式的存在与否，可以在这种异质结构中诱导拓扑相变。我们讨论了我们的结果和结论在未来实验中的相关性和实现方式。
