Linear plasmon dispersion in single-wall carbon nanotubes and the collective excitation spectrum of graphene
Linear plasmon dispersion in single-wall carbon nanotubes and the collective excitation spectrum of graphene
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DOI：
10.1103/physrevlett.100.196803
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发表时间：
2008-05-16
影响因子：
8.6
通讯作者：
Pichler, T.
中科院分区：
文献类型：
--
作者：
Kramberger, C.;Hambach, R.;Pichler, T.
我们已经测量了一个严格的线性π等离激元分散沿着轴的单独的单壁碳纳米管，这是完全不同的等离激元分散石墨或捆绑的单壁碳纳米管。基于石墨烯的系统的比较从头算研究使我们能够再现不同的分散体。这表明个体化的纳米管为石墨烯的集体电子激发提供了可行的实验途径，并且它验证了使用石墨烯来理解碳纳米管的电子激发。特别是，计算表明，局部场效应导致电子跃迁的混合，包括“狄拉克锥”，导致观察到的线性色散。
We have measured a strictly linear pi plasmon dispersion along the axis of individualized single-wall carbon nanotubes, which is completely different from plasmon dispersions of graphite or bundled single-wall carbon nanotubes. Comparative ab initio studies on graphene-based systems allow us to reproduce the different dispersions. This suggests that individualized nanotubes provide viable experimental access to collective electronic excitations of graphene, and it validates the use of graphene to understand electronic excitations of carbon nanotubes. In particular, the calculations reveal that local field effects cause a mixing of electronic transitions, including the "Dirac cone," resulting in the observed linear dispersion.