• 文献标题:   Exact Diagonalization for Magic-Angle Twisted Bilayer Graphene
  • 文献类型:   Article
  • 作  者:   POTASZ P, XIE M, MACDONALD AH
  • 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:  
  • 被引频次:   21
  • DOI:   10.1103/PhysRevLett.127.147203
  • 出版年:   2021

▎ 摘  要

We report on finite-size exact-diagonalization calculations in a Hilbert space defined by the continuum-model flat moire bands of magic angle twisted bilayer graphene. For moire band filling 3 > vertical bar v vertical bar > 2, where superconductivity is strongest, we obtain evidence that the ground state is a spin ferromagnet. Near vertical bar v vertical bar = 3, we find Chern insulator ground states that have spontaneous spin, valley, and sublattice polarization, and demonstrate that the anisotropy energy in this order-parameter space is strongly band-filling-factor dependent. We emphasize that inclusion of the remote band self-energy is necessary for a reliable description of magic angle twisted bilayer graphene flat band correlations.