文献类型：期刊文献

英文题名：Tuning corner states in proximitized second-order topological insulators with bulk-boundary obstruction

作者：Xue, Yang[1];Zhou, Tong[2,3];Xu, Wei[1];Zhao, Bao[4,5,6,7];Zutic, Igor[3];Yang, Zhongqin[4,5,6,8]

机构：[1]East China Univ Sci & Technol, Dept Phys, Shanghai 200237, Peoples R China;[2]Eastern Inst Technol, Eastern Inst Adv Study, Ningbo 315200, Zhejiang, Peoples R China;[3]SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA;[4]Fudan Univ, State Key Lab Surface Phys, Shanghai 200433, Peoples R China;[5]Fudan Univ, Key Lab Computat Phys Sci MOE, Shanghai 200433, Peoples R China;[6]Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China;[7]Liaocheng Univ, Sch Phys Sci & Informat Technol, Shandong Key Lab Opt Commun Sci & Technol, Liaocheng 252059, Peoples R China;[8]Shanghai Qi Zhi Inst, Shanghai 200030, Peoples R China

年份：2023

卷号：108

期号：16

外文期刊名：PHYSICAL REVIEW B

收录：;EI(收录号：20234815107628);WOS:【SCI-EXPANDED(收录号:WOS:001095000300001)】；

基金：Acknowledgments. We thank Dr. Zhongbo Yan for a very helpful discussion. This work was supported by National Natural Science Foundation of China under Grants No. 11904101, No. 11604134, No. 11874117, and No. 12174059, the Natural Science Foundation of Shanghai under Grant No. 21ZR1408200, and the U.S. DOE, Office of Science BES, Grant No. DE-SC0004890.

语种：英文

外文关键词：Electric insulators - Quantum theory - Topological insulators - Topology - Van der Waals forces

摘要：Second-order topological insulators (SOTIs) support topological states beyond the usual bulk-boundary correspondence and provide important connections between quantum chemistry and topology. A hallmark of the two-dimensional (2D) SOTIs is the emergence of corner states, which usually arise from the topologically nontrivial obstructed states in the bulk. In contrast, we reveal a very different scenario where even trivial obstructed bulk states can induce corner states due to their open boundaries. Remarkably, we show that these two types of corner states can coexist in a single system and predict, from first-principles calculations, that the monolayer C2N is a promising candidate for their observation. To overcome the limitation in manipulating corner states, we demonstrate it can be accomplished using a magnetic exchange field, where the corner states can be fully spin polarized and moved into the bulk states. Focusing on the example of the C2N/CrI3 van der Waals heterostructure, we put forth a class of proximitized materials which enable the versatile control of corner states through strain-controlled magnetic proximity effects. Our work reveals another type of topological state, and provides a universal proposal for topological corner state modulations and applications.