Dielectric function, screening, and plasmons in two-dimensional graphene
Dielectric function, screening, and plasmons in two-dimensional graphene
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DOI：
10.1103/physrevb.75.205418
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发表时间：
2007-05-01
影响因子：
3.7
通讯作者：
Das Sarma, S.
中科院分区：
文献类型：
--
作者：
Hwang, E. H.;Das Sarma, S.
在自洽场近似下，计算了二维石墨烯在任意波矢q和频率ω下的动态介电函数ε（q，ω）。结果被用来找到的等离子体激元模式的色散和静电屏蔽的库仑相互作用在二维（2D）的石墨烯层内的随机相位近似。在长波长（q -> 0）处，等离子体激元色散表现出局部经典行为omega（cl）=omega（0）root q，但等离子体频率的密度依赖性（omega（0）与n（1/4）成比例）不同于通常的2D电子系统（omega（0）与n（1/2）成比例）。依赖于波矢的等离子体色散和静态屏蔽函数表现出非常不同的行为比通常的2D情况下。我们表明，静态石墨烯屏蔽的固有带间贡献可以有效地吸收在背景介电常数。
The dynamical dielectric function of two-dimensional graphene at arbitrary wave vector q and frequency omega, epsilon(q,omega), is calculated in the self-consistent-field approximation. The results are used to find the dispersion of the plasmon mode and the electrostatic screening of the Coulomb interaction in two-dimensional (2D) graphene layer within the random-phase approximation. At long wavelengths (q -> 0), the plasmon dispersion shows the local classical behavior omega(cl)=omega(0)root q, but the density dependence of the plasma frequency (omega(0)proportional to n(1/4)) is different from the usual 2D electron system (omega(0)proportional to n(1/2)). The wave-vector-dependent plasmon dispersion and the static screening function show very different behavior than the usual 2D case. We show that the intrinsic interband contributions to static graphene screening can be effectively absorbed in a background dielectric constant.