• 文献标题:   Emergent Geometric Frustration and Flat Band in Moire Bilayer Graphene
  • 文献类型:   Article
  • 作  者:   PAL HK, SPITZ S, KINDERMANN M
  • 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:   Georgia Inst Technol
  • 被引频次:   7
  • DOI:   10.1103/PhysRevLett.123.186402
  • 出版年:   2019

▎ 摘  要

So far the physics of moire graphene bilayers at large, incommensurate rotation angles has been considered uninteresting. It has been held that the interlayer coupling in such structures is weak and the system can be thought of as a pair of decoupled single graphene sheets to a good approximation. Here, we demonstrate that for large rotation angles near commensurate ones, the interlayer coupling, far from being weak, is able to completely localize electrons to within a large scale, geometrically frustrated network of topologically protected modes. The emergent geometric frustration of the system gives rise to completely flat bands, with strong correlation physics as a result. All of this arises although in the lattice structure no large scale pattern appears to the unguided eye. Sufficiently close to commensuration the low-energy physics of this remarkable system has an exact solution.