期刊
PHYSICAL REVIEW B
卷 81, 期 8, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.81.085416
关键词
-
资金
- Natural Sciences and Engineering Research Council of Canada
We solve a nonlinear integral equation for the electrostatic potential in doped graphene due to an external charge, arising from a Thomas-Fermi (TF) model for screening by graphene's pi electron bands. In particular, we study the effects of a finite equilibrium charge-carrier density in graphene, nonzero temperature, nonzero gap between graphene and a dielectric substrate, as well as the nonlinearity in the band density of states. Effects of the exchange and correlation interactions are also briefly discussed for undoped graphene at zero temperature. Nonlinear results are compared with both the linearized TF model and the dielectric screening model within random-phase approximation (RPA). In addition, image potential of the external charge is evaluated from the solution of the nonlinear integral equation and compared to the results of linear models. We have found generally good agreement between the results of the nonlinear TF model and the RPA model in doped graphene, apart from Friedel oscillations in the latter model. However, relatively strong nonlinear effects are found in the TF model to persist even at high doping densities and large distances of the external charge.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据