The effects of Moire lattice on the electronic properties of graphene
arXiv:1706.05345 · doi:10.1103/PhysRevB.96.035411
Abstract
We study structural and electronic properties of graphene grown on SiC substrate using scanning tunneling microscope (STM), spot-profile-analysis low energy electron diffraction (SPA-LEED) and angle resolved photoemission spectroscopy (ARPES). We find several new replicas of Dirac cones in the Brillouin zone (BZ). Their locations can be understood in terms of combination of basis vectors linked to SiC 6x6 and graphene 6xsqrt(3) x 6sqrt(3) reconstruction. Therefore these new features originate from the Moie caused by the lattice mismatch between SiC and graphene. More specifically, Dirac cones replicas are caused by underlying weak modulation of the ionic potential by the substrate that is then experienced by the electrons in the graphene. We also demonstrate that this effect is equally strong in single and tri-layer graphene, therefore the additional Dirac cones are intrinsic features rather than result of photoelectron diffraction. These new features in the electronic structure are very important for the interpretation of recent transport measurements and can assist in tuning the properties of graphene for practical applications.
6 pages, 2 figures
References in corpus (10)
- Ultrahigh electron mobility in suspended graphene
- Suspended Graphene: a bridge to the Dirac point
- Substrate-induced band gap opening in epitaxial graphene
- Anisotropic behaviors of massless Dirac fermions in graphene under periodic potential
- New Generation of Massless Dirac Fermions in Graphene under External Periodic Potentials
- Metal to insulator transition in epitaxial graphene induced by molecular doping
- Hierarchy of Hofstadter states and replica quantum Hall ferromagnetism in graphene superlattices
- Symmetry Breaking in Few Layer Graphene Films
- Morphology of graphene thin film growth on SiC(0001)
- Characterization of graphene through anisotropy of constant-energy maps in angle-resolved photoemission