Engineering corner states by coupling two-dimensional topological insulators
Date
2025-01-06
Journal Title
Journal ISSN
Volume Title
Publisher
Physical Review B
Abstract
We theoretically find that the second-order topological insulator, i.e., corner states, can be engineered by coupling two copies of two-dimensional ℤ2 topological insulators with opposite spin helicities. As concrete examples, we utilize Kane-Mele models (i.e., graphene with intrinsic spin-orbit coupling) to realize the corner states by setting the respective graphenes as ℤ2 topological insulators with opposite intrinsic spin-orbit couplings. To exhibit its universality, we generalize our findings to other representative ℤ2 topological insulators, e.g., the Bernevig-Hughes-Zhang model. An effective model is presented to reveal the physical origin of the corner states. We further show that the corner states can also be designed in other topological systems, e.g., by coupling quantum anomalous Hall systems with opposite Chern numbers. Our work suggests that interlayer coupling can be treated as a simple and efficient strategy to drive two-dimensional lower-order topological insulators to the higher-order ones.
Description
This article was originally published in Physical Review B. The version of record is available at: https://doi.org/10.1103/PhysRevB.111.045403.
©2025 American Physical Society.
Keywords
electronic structure, quantum phase transitions, topological materials, topological phases of matter
Citation
Liu, Lizhou, Jiaqi An, Yafei Ren, Ying-Tao Zhang, Zhenhua Qiao, and Qian Niu. “Engineering Corner States by Coupling Two-Dimensional Topological Insulators.” Physical Review B 111, no. 4 (January 6, 2025): 045403. https://doi.org/10.1103/PhysRevB.111.045403.