• 文献标题:   Relaxation of charge in monolayer graphene: Fast nonlinear diffusion versus Coulomb effects
  • 文献类型:   Article
  • 作  者:   KOLOMEISKY EB, STRALEY JP
  • 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:   Univ Virginia
  • 被引频次:   0
  • DOI:   10.1103/PhysRevB.95.045415
  • 出版年:   2017

▎ 摘  要

Pristine monolayer graphene exhibits very poor screening because the density of states vanishes at the Dirac point. As a result, charge relaxation is controlled by the effects of zero-point motion (rather than by the Coulomb interaction) over a wide range of parameters. Combined with the fact that graphene possesses finite intrinsic conductivity, this leads to a regime of relaxation described by a nonlinear diffusion equation with a diffusion coefficient that diverges at zero charge density. Some consequences of this fast diffusion are self-similar superdiffusive regimes of relaxation, the development of a charge depleted region at the interface between electron-and hole-rich regions, and finite extinction times for periodic charge profiles.