• 文献标题:   Optical absorption of twisted bilayer graphene with interlayer potential asymmetry
  • 文献类型:   Article
  • 作  者:   MOON P, SON YW, KOSHINO M
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   1098-0121 EI 1550-235X
  • 通讯作者地址:   New York Univ Shanghai
  • 被引频次:   19
  • DOI:   10.1103/PhysRevB.90.155427
  • 出版年:   2014

▎ 摘  要

We investigate the band structure and the optical absorption spectrum of twisted bilayer graphenes with changing interlayer bias and Fermi energy simultaneously. We show that the interlayer bias lifts the degeneracy of the superlattice Dirac point, while the amount of the Dirac point shift is significantly suppressed in small rotation angles, and even becomes opposite to the applied bias. We calculate the optical absorption spectrum in various asymmetric potentials and Fermi energies, and associate the characteristic spectral features with the band structure. The spectroscopic features are highly sensitive to the interlayer bias and the Fermi energy, and widely tunable by the external field effect.