Internal Mobility Edge in Doped Graphene: Frustration in a Renormalized Lattice
Internal Mobility Edge in Doped Graphene: Frustration in a Renormalized Lattice
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DOI：
10.2529/piers071107141648
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发表时间：
2007-07
期刊：
影响因子：
--
通讯作者：
G. Naumis
中科院分区：
文献类型：
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作者：
G. Naumis
通过在分裂带中引入杂质或在晶格中产生空位，可以在石墨烯的费米能级附近出现内局域化迁移率边。与通常的局部化图像不同，边缘出现在光谱的中心，而不是在频带边缘。对这一结果的解释是，晶格的二体性质允许重整化哈密顿量，并且在重整化的晶格中由于受挫效应而出现内边。局域态光谱区域的能量大小与在窄禁带半导体中观察到的能量大小相似。
We show that an internal localization mobility edge can appear around the Fermi energy in graphene by introducing impurities in the split-band regimen, or by producing vacancies in the lattice. The edge appears at the center of the spectrum and not at the band edges, in contrast with the usual picture of localization. Such result is explained by showing that the bipartite nature of lattice allows to renormalize the Hamiltonian, and the internal edge appears because of frustration efiects in the renormalized lattice. The size in energy of the spectral region with localized states is similar in value to that observed in narrow gap semiconductors.