One-phonon resonant Raman scattering: Fröhlich exciton-phonon interaction.
One-phonon resonant Raman scattering: Fröhlich exciton-phonon interaction.
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单声子共振拉曼散射：Fröhlich 激子-声子相互作用。
DOI：
10.1103/physrevb.40.4030
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Cardona
中科院分区：
文献类型：
--
作者：
Trallero;Cantarero;Cardona
给出了以激子为中间态的单LO声子的禁戒拉曼散射的显式表达式。该理论可以应用于低于和高于激子能量的光子频率。对应于不同的激子状态之间的跃迁的矩阵元素的解析计算。的平方拉曼极化率的不同的贡献进行了比较，最重要的一个被发现是由于离散连续的过渡。它示出在这种情况下，在拉曼效率的出射共振总是高于传入的，在所有的III-V族化合物半导体实验中看到的特性。从理论模型出发，给出了应用自由电子空穴对理论的一般判据，即激子玻尔半径。分析了允许散射和禁止散射之间的干涉效应，并与自由电子空穴对理论进行了定性和定量的比较。拉曼极化率的绝对值计算和比较最近的测量GaP，产生一个很好的协议，而不使用任何拟合参数。
An explicit expression for forbidden Raman scattering by one LO phonon with excitons as intermediate states is given. The theory can be applied at photon frequencies below and above the exciton energy. The matrix elements corresponding to transitions between different exciton states are calculated analytically. The different contributions to the squared Raman polarizability are compared; the most important one is found to be due to discrete-continuous transitions. It is shown in this case that the outgoing resonance in the Raman efficiency is always higher than the incoming one, a peculiarity seen experimentally in all III-V compound semiconductors. From the theoretical model a general criterion for the application of the free--electron-hole--pair theory is given in terms of the exciton Bohr radius. An analysis of the interference effect between the allowed and forbidden scattering is presented, and qualitative and quantitative differences with the free--electron-hole--pair theory are discussed. Absolute values of Raman polarizabilities are calculated and compared with recent measurements for GaP, yielding a good agreement without the use of any fit parameter.