• 文献标题:   Higher-Order Topological Insulator in Twisted Bilayer Graphene
  • 文献类型:   Article
  • 作  者:   PARK MJ, KIM Y, CHO GY, LEE S
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW LETTERS
  • ISSN:   0031-9007 EI 1079-7114
  • 通讯作者地址:   Korea Adv Inst Sci Technol
  • 被引频次:   17
  • DOI:   10.1103/PhysRevLett.123.216803
  • 出版年:   2019

▎ 摘  要

Higher-order topological insulators are newly proposed topological phases of matter, whose bulk topology manifests as localized modes at two- or higher-dimensional lower boundaries. In this Letter, we propose the twisted bilayer graphenes with large angles as higher-order topological insulators, hosting topological corner charges. At large commensurate angles, the intervalley scattering opens up the bulk gap and the corner states occur at half filling. Based on both first-principles calculations and analytic analysis, we show the striking results that the emergence of the corner states do not depend on the choice of the specific angles as long as the underlying symmetries are intact. Our results show that the twisted bilayer graphene can serve as a robust candidate material of a two-dimensional higher-order topological insulator.