晶格热振动对准二维强耦合极化子有效质量的影响

采用Tokuda改变的线性组合算符法和改进的LLP变分法，研究了晶格热振动对无限势垒量子阱中电子与界面光学声子强耦合、与体纵光学声子弱耦合系统的影响，推导出作为阱宽和温度函数的极化子有效质量的表达式. 尤其得到了量子阱中极化子的振动频率及其随阱宽和温度变化的规律. 对KI/AgCl/KI量子阱进行了数值计算，结果表明，极化子的振动频率和有效质量随阱宽的增加而减小、随温度的升高而减小，但不同支声子与电子相互作用对极化子的振动频率和有效质量的贡献以及它们随阱宽和温度的变化情况大不相同. 关键词： 量子阱 强耦合极化子 振动频率 有效质量 温度依赖性

Effects of lattice vibration on the effective mass of quasi-two-dimensional strong-coupling polaron

The effects of lattice vibration on the system in which the electron is weakly coupled with bulk longitudinal optical phonons and strongly coupled with interfac e optical phonons in an infinite quantum well were studied by using Tokuda' line ar-combination operator and a modified LLP variational method. The expressions for the effective mass of the polaron in a quantum well QW as functions of the we ll's width and temperature were derived. In particular, the law of the change of the vibration frequency of the polaron changing with well's width and temperatu re are obtained. Numerical results of the effective mass and the vibration frequ ency of the polaron for KI/AgCl/KI QW show that the vibration frequency and the effective mass of the polaron decrease with increasing well's width and temperat ure, but the contribution of the interaction between the electron and the differ ent branches of phonons to the effective mass and the vibration frequency and th e change of their variation with the well's width and temperature are greatly di fferent.