Spectral approach to transport in a two-dimensional honeycomb lattice with substitutional disorder
Spectral approach to transport in a two-dimensional honeycomb lattice with substitutional disorder
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DOI：
10.1103/physrevb.99.024115
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发表时间：
2017-11
影响因子：
3.7
通讯作者：
E. Kostadinova;C. Liaw;A. Hering;A. Cameron;F. Guyton;L. Matthews;T. Hyde
中科院分区：
文献类型：
--
作者：
E. Kostadinova;C. Liaw;A. Hering;A. Cameron;F. Guyton;L. Matthews;T. Hyde
利用二维渗流问题的谱方法，数值研究了无序二维蜂窝晶格的输运性质，其特征在于一个安德森型哈密顿量。在我们的模型中，无序由两个参数表示：一个随机的在位能量分布${\ensuremath{\displaystyle {\math}}_{i}$（位置无序）和掺杂能量浓度$p$（替代无序）。结果表明，在临界掺杂浓度为0. 3%时，非零无序的扩展能态的存在以及向局域行为的转变，与实验观察到的氢掺杂石墨烯片的金属-绝缘体转变一致.
The transport properties of a disordered two-dimensional (2D) honeycomb lattice are examined numerically using the spectral approach to the 2D percolation problem, characterized by an Anderson-type Hamiltonian. In our model, disorder is represented by two parameters: a distribution of random on-site energies ${\ensuremath{\epsilon}}_{i}$ (positional disorder) and a concentration of doping energies $p$ (substitutional disorder). The results indicate the existence of extended energy states for nonzero disorder and the emergence of a transition towards localized behavior for critical doping concentration ${n}_{D}g0.3%$, in agreement with the experimentally observed metal-to-insulator transition in a graphene sheet doped with hydrogen.