• 文献标题:   Defect-induced magnetism and Yu-Shiba-Rusinov states in twisted bilayer graphene
  • 文献类型:   Article
  • 作  者:   LOPEZBEZANILLA A, LADO JL
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW MATERIALS
  • ISSN:   2475-9953
  • 通讯作者地址:   Los Alamos Natl Lab
  • 被引频次:   3
  • DOI:   10.1103/PhysRevMaterials.3.084003
  • 出版年:   2019

▎ 摘  要

Atomic defects have a significant impact on the low-energy properties of graphene systems. By means of first-principles calculations and tight-binding models we provide evidence that chemical impurities modify both the normal and the superconducting states of twisted bilayer graphene. A single hydrogen atom attached to the bilayer surface yields a triple-point crossing, whereas self-doping and threefold symmetry breaking are created by a vacant site. Both types of defects lead to time-reversal symmetry breaking and the creation of local magnetic moments. Hydrogen-induced magnetism is found to exist also at the doping levels where superconductivity appears in magic-angle graphene superlattices. As a result, the coexistence of superconducting order and defectinduced magnetism yields in-gap Yu-Shiba-Rusinov excitations in magic-angle twisted bilayer graphene.