• 文献标题:   Magnetism near half-filling of a Van Hove singularity in twisted graphene bilayer
  • 文献类型:   Article
  • 作  者:   LIU YW, QIAO JB, YAN C, ZHANG Y, LI SY, HE L
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Beijing Normal Univ
  • 被引频次:   16
  • DOI:   10.1103/PhysRevB.99.201408
  • 出版年:   2019

▎ 摘  要

Twisted graphene bilayers (TGBs) with slight twist angle always have low-energy Van Hove singularities (VHSs) that are strongly localized around AA-stacked regions of the moire pattern. The localized VHSs are strongly related to novel correlated quantum states, such as Mott-like insulating phase and unconventional superconductivity, observed in the slightly TGBs. Here we studied the electronic properties of a TGB with theta similar to 1.64 degrees and demonstrated that a VHS splits into two spin-polarized states flanking the Fermi energy when the VHS is close to the Fermi level. Such a result indicates that localized magnetic moments emerge in the AA-stacked regions of the TGB. Since the low-energy VHSs can be reached in slightly TGBs, our result therefore provides a facile direction to realize novel quantum phases in graphene system.