• 文献标题:   Effective continuum model for relaxed twisted bilayer graphene and moire electron-phonon interaction
  • 文献类型:   Article
  • 作  者:   KOSHINO M, NAM NNT
  • 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:   Osaka Univ
  • 被引频次:   2
  • DOI:   10.1103/PhysRevB.101.195425
  • 出版年:   2020

▎ 摘  要

We construct an analytic continuum model to describe the electronic structure and the electron-phonon interaction in twisted bilayer graphenes with arbitrary lattice deformation. Starting from the tight-binding model, we derive the interlayer Hamiltonian in the presence of general lattice displacement and obtain a long-wavelength continuum expression for smooth deformation. We show that the continuum model correctly describes the band structures of the lattice-relaxed twisted bilayer graphenes. We apply the formula to the phonon vibration and derive an explicit expression of the electron-phonon matrix elements between the moire band states and the moire phonon modes. By numerical calculation, we find that the electron-phonon coupling is significantly enhanced in low twist angles due to the superlattice hybridization. At the magic angle, in particular, the phonon-mediated electron-electron interaction is found to be comparable to the order of the inverse density of states, suggesting that the system is in the strong coupling regime.