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arXiv 0803.3847cond-mat.mes-hallcond-mat.mtrl-sci
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金属碳纳米管中曲率引起的光学声子频移

Curvature induced optical phonon frequency shift in metallic carbon nanotubes

K. Sasaki, R. Saito, G. Dresselhaus, M. S. Dresselhaus, H. Farhat, J. Kong

摘要:

从理论上研究了碳纳米管中$Γ$点纵光学(LO)和点横光学(TO)声子模频率的量子修正。TO声子模的频移和展宽强烈依赖于由于碳纳米管中特殊的电子-声子耦合引起的曲率效应,这通过不同纳米管手性的频移的费米能量依赖性来显示。研究还表明,由于局域规范对称性,在$Γ$点附近的TO模是电子的散射,由于时间反演对称性,LO模和TO模之间没有声子混合。理论和实验进行了比较。

英文摘要:

The quantum corrections to the frequencies of the $Γ$ point longitudinal optical (LO) and transverse optical (TO) phonon modes in carbon nanotubes are investigated theoretically. The frequency shift and broadening of the TO phonon mode strongly depend on the curvature effect due to a special electron-phonon coupling in carbon nanotubes, which is shown by the Fermi energy dependence of the frequency shift for different nanotube chiralities. It is also shown that the TO mode near the $Γ$ point decouples from electrons due to local gauge symmetry and that a phonon mixing between LO and TO modes is absent due to time-reversal symmetry. Some comparison between theory and experiment is presented.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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