INTERBAND EFFECT OF LATTICE VIBRATIONS IN EXCITON ABSORPTION SPECTRA
INTERBAND EFFECT OF LATTICE VIBRATIONS IN EXCITON ABSORPTION SPECTRA
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DOI：
10.1016/0022-3697(64)90162-3
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发表时间：
1964-01-01
影响因子：
4
通讯作者：
TOYOZAWA, Y
中科院分区：
文献类型：
--
作者：
TOYOZAWA, Y
本文提出了激子吸收谱线型的一般理论，它精确地考虑了激子-声子耦合的带间效应和带内效应。给出了两种等效的线形表达式。第一个，这可以得到一个启发式的方式从二阶微扰理论的间接过程，但推导出完全与使用广义阻尼理论，包含在能量分母，移动和衰减矩阵，它具有不同的激子带之间的非对角元素。对角化的重整化能量矩阵导致第二个表达式-可加性规则。根据这一规则，整个激子谱可以被分解成分量，如果宽度足够小，每个分量都是非对称的洛伦兹形状，并且在这个宽度内重整化量的能量依赖性可以忽略不计。一般表达式中不仅包含了以前得到的结果，而且还包含了各种高阶效应。将理论与观测进行比较，并对激子谱的分析作一些有益的评论。
A general theory of the line shape of exciton absorption spectra is presented, in which the interband as well as intraband effects of exciton-phonon coupling are exactly taken into account. Two equivalent expressions for the line shape are given. The first one, which can be obtained in a heuristic way starting from the second order perturbation theory for the indirect process, but is derived exactly with the use of generalized damping theory, contains, in the energy denominator, the shift and decay matrix which has non-diagonal elements between different exciton bands. Diagonalization of the renormalized energy matrix leads to the second expression—the additivity rule. According to this rule, the whole of the exciton spectra can be decomposed into components, each of which is of asymmetric Lorentzian shape if the width is sufficiently small and the energy dependences of renormalized quantities can be neglected within this width. Not only the results obtained previously, but also various higher order effects are included in the general expressions. Comparison of theory with observations, and a few remarks useful for the analysis of exciton spectra, will be made.