极性晶体膜中强耦合激子的性质

摘要

在强耦合极化子模型基础上，采用Lee-Low-Pines( LLP)变分法研究了极性晶体膜中激子与表面光学( SO)声子强耦合、与体纵光学( LO)声子弱耦合体系的性质。讨论了极性晶体膜中激子的诱生势与膜厚度和温度的变化关系。结果表明：激子的诱生势不仅与电子-空穴间距离有关，而且与极性晶体膜厚度有关，同时温度对激子诱生势的影响十分显著。%The properties of the exciton interaction with both the weak-coupling bulk longitudinal-optical ( LO ) phonons and strong-coupling surface-optical( SO) phonons in a slab of polar crystal are studied by using the Lee-Low-Pines( LLP) variational method based on the model of strong-coupling polaron. The relationships between the induced potential of the exciton in a polar crystal slab and the thickness of slab and temperature are derived. The results show that the induced potential of the exciton is related not only to the distance between electron and hole,but also to the thickness of slab,and the influence of temperature on the induced potential is notable.