• 文献标题:   Energy-Dependent Chirality Effects in Quasifree-Standing Graphene
  • 文献类型:   Article
  • 作  者:   DOMBROWSKI D, JOLIE W, PETROVIC M, RUNTE S, CRAES F, KLINKHAMMER J, KRALJ M, LAZIC P, SELA E, BUSSE C
  • 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:   Westfal Wilhelms Univ Munster
  • 被引频次:   7
  • DOI:   10.1103/PhysRevLett.118.116401
  • 出版年:   2017

▎ 摘  要

We present direct experimental evidence of broken chirality in graphene by analyzing electron scattering processes at energies ranging from the linear (Dirac-like) to the strongly trigonally warped region. Furthermore, we are able to measure the energy of the van Hove singularity at the M point of the conduction band. Our data show a very good agreement with theoretical calculations for free-standing graphene. We identify a new intravalley scattering channel activated in case of a strongly trigonally warped constant energy contour, which is not suppressed by chirality. Finally, we compare our experimental findings with T-matrix simulations with and without the presence of a pseudomagnetic field and suggest that higher order electron hopping effects are a key factor in breaking the chirality near to the van Hove singularity.