第一个光学声子模式对于碳纳米管声子输运的影响

Role of the first optical phonon mode in phonon transport of carbon nanotubes

考虑第一个光学声子模式的影响,我们计算了碳纳米管的Umklapp过程的声子驰豫率和热导率。计算结果表明第一个光学模式能够极大地增强声子驰豫率。随着碳纳米管管径的增大,考虑和不考虑第一个光学声子模式所得到的驰豫率的差异将逐渐增大。此外,驰豫率的增大导致了驰豫时间和热导率的降低,并简要地分析了第一个光学声子模式对于热导率的影响。

We calculate the relaxation rate of Umklapp process and thermal conductivity by considering the first optical phonon mode. The results show that the enhancement of relaxation rate appears when the first optical phonon mode is considered. As the diameter increases, the difference of relaxation rate between with and without the optical mode increases. Moreover, the increase of relaxation rate results in the reduction of relaxation time and thermal conductivity. A simple but smart analysis about the reduction is presented.