Observation of Distinct Electron-Phonon Couplings in Gated Bilayer Graphene
Observation of Distinct Electron-Phonon Couplings in Gated Bilayer Graphene
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DOI：
10.1103/physrevlett.101.257401
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发表时间：
2008-12-19
影响因子：
8.6
通讯作者：
Pimenta, M. A.
中科院分区：
文献类型：
--
作者：
Malard, L. M.;Elias, D. C.;Pimenta, M. A.
对背栅双层石墨烯样品进行了拉曼研究。由电荷转移引起的费米能级的变化分裂了拉曼G带，使其较高的分量硬化，而使较低的分量软化。这两个分量与两层中原子的对称振动（S）和反对称振动（AS）有关，后者由于反转对称破缺而变得拉曼活跃。声子硬化和软化的解释考虑的S和AS声子与带间和带内电子空穴对的选择性耦合。
A Raman study of a back gated bilayer graphene sample is presented. The changes in the Fermi level induced by charge transfer splits the Raman G band, hardening its higher component and softening the lower one. These two components are associated with the symmetric (S) and antisymmetric vibration (AS) of the atoms in the two layers, the later one becoming Raman active due to inversion symmetry breaking. The phonon hardening and softening are explained by considering the selective coupling of the S and AS phonons with interband and intraband electron-hole pairs.