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arXiv 0903.1771cond-mat.mes-hall
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碳纳米管中的声子-声子相互作用和声子阻尼

Phonon-phonon interactions and phonon damping in carbon nanotubes

A. De Martino, R. Egger, A. O. Gogolin

摘要:

在连续介质弹性理论的框架下,我们建立并研究了碳纳米管中长波长声学声子相互作用的有效低能量子理论。给出了三声子和四声子过程的一般解析推导,并根据少量弹性系数确定了相关的耦合常数。由于低维和抛物色散,非相互作用弯曲声子的有限温度密度发散,和一个非微扰的方法来处理它们的相互作用是必要的。在一个平均场的描述,我们发现,一个动态的差距打开。在实践中,该间隙被热涂抹,但仍然具有重要的后果。利用我们的理论,我们计算了由于声子-声子和电子-声子相互作用的声学声子的衰减率,这意味着它们的品质因数的上限。

英文摘要:

We formulate and study the effective low-energy quantum theory of interacting long-wavelength acoustic phonons in carbon nanotubes within the framework of continuum elasticity theory. A general and analytical derivation of all three- and four-phonon processes is provided, and the relevant coupling constants are determined in terms of few elastic coefficients. Due to the low dimensionality and the parabolic dispersion, the finite-temperature density of noninteracting flexural phonons diverges, and a nonperturbative approach to their interactions is necessary. Within a mean-field description, we find that a dynamical gap opens. In practice, this gap is thermally smeared, but still has important consequences. Using our theory, we compute the decay rates of acoustic phonons due to phonon-phonon and electron-phonon interactions, implying upper bounds for their quality factor.

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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