碱卤晶体中激子-声子相互作用与光吸收谱线宽

本文研究对碱卤晶体中电荷转移型激子(charge transfer exciton,简写为CTE)的性质有重要影响的激子-声子相互作用。讨论了一类可能起重要作用的相互作用机制:离子的位移振动对CTE系统的哈密顿量的调制,从而导出了CTE与声子系统的相互作用哈密顿量,还讨论了相互作用导致的CTE的有限寿命及与之相联系的光吸收谱线宽,并在适当的近似下作自洽的数值计算,得到的线宽数据与实验测定值半定量相符。这说明本文导出的相互作用哈密顿量很可能是碱卤晶体中起重要作用的激子-声子相互作用。关键词：

EXCITON-PHONON INTERACTION IN ALKALI HALIDE CRYSTALS

This article deals with the exciton-phonon interaction which has important effects on the properties of the charge transfer excitons (CTE) in alkali halide crystals. An interaction mechanism: the modulation of the Hamiltonian of the CTE system by the vibrations of the constituent ions, which may play an important role, is studied. The CTE-phonon interaction Hamiltonian is derived. From this interaction Hamiltonian, we have discussed the lifetime of the CTE. The linewidths calculated self-consistently under proper approximations agree semiquantitatively with the data measured by experiments in the literature. So we consider that this interaction Hamiltonian may present the important exciton-phonon interaction in alkali halide crystals.