• 文献标题:   Dynamic polarization of graphene by moving external charges: Random phase approximation
  • 文献类型:   Article
  • 作  者:   ALLISON KF, BORKA D, RADOVIC I, HADZIEVSKI L, MISKOVIC ZL
  • 作者关键词:   carrier density, dielectric function, dynamic nuclear polarisation, electrochemistry, electron energy loss spectra, graphene, rpa calculation
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   1098-0121 EI 1550-235X
  • 通讯作者地址:   Univ Waterloo
  • 被引频次:   36
  • DOI:   10.1103/PhysRevB.80.195405
  • 出版年:   2009

▎ 摘  要

We evaluate the stopping and image forces on a charged particle moving parallel to a doped sheet of graphene by using the dielectric-response formalism for graphene's pi-electron bands in the random phase approximation (RPA). The forces are presented as functions of the particle speed and the particle distance for a broad range of charge-carrier densities in graphene. A detailed comparison with the results from a kinetic equation model reveal the importance of interband single-particle excitations in the RPA model for high particle speeds. We also consider the effects of a finite gap between graphene and a supporting substrate, as well as the effects of a finite damping rate that is included through the use of Mermin's procedure. The damping rate is estimated from a tentative comparison of the Mermin loss function with a high-resolution reflection electron energy loss spectroscopy experiment. In the limit of low particle speeds, several analytical results are obtained for the friction coefficient that show an intricate relationship between the charge-carrier density, the damping rate, and the particle distance, which may be relevant to surface processes and electrochemistry involving graphene.