Polarization charge distribution in gapped graphene : Perturbation theory and exact diagonalization analysis
Polarization charge distribution in gapped graphene : Perturbation theory and exact diagonalization analysis
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DOI：
10.1103/physrevb.78.075433
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发表时间：
2008-06
影响因子：
3.7
通讯作者：
V. Kotov;V. M. Pereira;B. Uchoa
中科院分区：
文献类型：
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作者：
V. Kotov;V. M. Pereira;B. Uchoa
我们研究了块状石墨烯中库仑杂质引起的真空极化电荷的分布。通过解析计算极化函数，我们证明了电荷密度在空间中以非平凡的方式分布，并且在由有效康普顿波长设定的特征长度尺度上分布。密度从低于这个标度的对数行为，到高于这个标度的指数变化。相应的紧束缚模型在有限尺寸晶格上的显式对角化证实了我们在连续统极限中的结果。文中还讨论了电子-电子相互作用效应。
We study the distribution of vacuum polarization charge induced by a Coulomb impurity in massive graphene. By analytically computing the polarization function, we show that the charge density is distributed in space in a non-trivial fashion, and on a characteristic length-scale set by the effective Compton wavelength. The density crosses over from a logarithmic behavior below this scale, to a power law variation above it. Our results in the continuum limit are confirmed by explicit diagonalization of the corresponding tight-binding model on a finite-size lattice. Electron-electron interaction effects are also discussed.