Quasiparticle dynamics in graphene
Quasiparticle dynamics in graphene
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DOI：
10.1038/nphys477
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发表时间：
2007-01-01
期刊：
影响因子：
19.6
通讯作者：
Rotenberg, Eli
中科院分区：
文献类型：
--
作者：
Bostwick, Aaron;Ohta, Taisuke;Rotenberg, Eli
石墨烯的电荷载流子--被称为狄拉克费米子--的有效无质量的相对论行为是其独特的电子结构的结果，其特征在于圆锥形的价带和导带在动量空间中的一个点处相遇（在狄拉克交叉能量处）。石墨烯和相关系统如碳纳米管、富勒烯和石墨中的电荷载流子之间的多体相互作用的研究是令人感兴趣的，因为它们对这些系统中的超导性和其他奇异基态的贡献。在这里，我们表明，使用角分辨光电子能谱，电子-等离子体激元耦合在重整周围的狄拉克交叉能量的带类似于普通金属中的电子-玻色子耦合的质量重整化中起着异常强大的作用。我们的研究结果表明，电子-电子，电子-等离子体激元和电子-声子耦合必须被认为是在平等的基础上，试图了解石墨烯和相关系统中的准粒子的动力学。
The effectively massless, relativistic behaviour of graphene's charge carriers-known as Dirac fermions-is a result of its unique electronic structure, characterized by conical valence and conduction bands that meet at a single point in momentum space (at the Dirac crossing energy). The study of many-body interactions amongst the charge carriers in graphene and related systems such as carbon nanotubes, fullerenes and graphite is of interest owing to their contribution to superconductivity and other exotic ground states in these systems. Here we show, using angle-resolved photoemission spectroscopy, that electron-plasmon coupling plays an unusually strong role in renormalizing the bands around the Dirac crossing energy-analogous to mass renormalization by electron-boson coupling in ordinary metals. Our results show that electron-electron, electron-plasmon and electron-phonon coupling must be considered on an equal footing in attempts to understand the dynamics of quasiparticles in graphene and related systems.