温度对激光场引起的纳米管声子增益影响

Effect of temperature on phonon amplification in a single-walled nanotube

讨论了强激光场下单壁纳米管的声子增益效应.采用含时微扰方法计算了不同温度下声子占据数随时间的变化率(声子增益系数).计算结果表明,在强激光场下纳米管中的声子占据数随时间非线性增加,增益系数与温度和激光场强都有关系.随着温度升高,声子增益系数迅速减小;在确定的温度情况下,激光场强越强,声子增益效应越明显,并对这个现象给出了合理的物理解释.

The phonon amplification effect occurring in a single-walled nanotube was discussed, and the change rates of phonon population at different temperatures were calculated by using a time-dependent-perturbation method. It is shown that the optical phonon population increases nonlinearly with increasing laser field and the rate decreases as the temperature increases. At a definite temperature, the more intense the laser field is, the more remarkable the phonon amplification effect is, and a reasonable interpretation on this phenomenon was presented.