多声子无辐射弛豫速率的理论研究

本文应用量子力学生成函数法,在等效耦合模条件下导出多声子弛豫速率的普适表达式,及在高级近似条件下的解析表达式。指出Fong等人在弱耦合条件下用统计方法、Miyakawa等人在弱耦合和低温近似条件下所得多声子弛豫速率表达式的局限性。文中还计算了多声子弛豫速率对温度、声子能量、能隙以及位移参数的依赖关系。

THEORETICAL STUDY OF MULTIPHONON RADIATIONLESS RELAXATION RATE

In this paper, with the assuption of effective lattice mode of coupling, a generalized theoretical expression of multiphonon relaxation rate has been derived by using quantum mechanical generating function method. An analytical rate expression is presented for high-order approximation case. Limitations of relaxation rate expressions in weak coupling approxamation given by Fong et al. with the quantum statistical method, and in weak coupling approximation and low temperature approximation given by Miyakawa et al. with quantum statistical method are pointed out. The dependence of the multiphonon relaxation rate on temperature, phonon. energy, energy gap and displacement parameter are also calculated.