准二维强耦合激子能量的温度依赖性

Temperature Dependence of the Energies of Quasi-Two-Dimensional Strong-Coupling Excitons

采用线性组合算符法和LLP变分法研究了晶格热振动和极化子效应对量子阱中激子与界面光学(IO)声子强耦合又与体纵光学(LO)声子弱、中耦合体系的基态和激发态的影响,推导出作为量子阱宽和温度函数的激子基态能量的移动和第一内部激发态能量的移动的表达式,以AgCl/AgBr/AgCl量子阱为例进行了数值计算.结果表明,由激子-IO声子强耦合所产生的激子基态能量移动和第一内部激发态能量移动随温度的升高而增大,而由激子-LO声子弱、中耦合所产生的激子基态能量移动和第一内部激发态能量移动随温度的升高而减小.

The influences of lattice vibration and polaron effects on the ground state and the excited state of the system, for which the exciton is strongly coupled with interface-optical （IO） phonons but weakly or intermediately coupled with bulk-longitudinal-optical （LO） phonons in a quantum well, are studied using the linear-combination operator and the LLP variational method. The expressions for the ground state energy shift and the first internal excited state energy shift of the exciton as a function of the well width and temperature are derived. Numerical calculations for an AgCl/AgBr/AgCl QW, for example, are performed. The results indicate that the ground state energy shift and the first internal excited state energy shift increases with the temperature for strong exciton-IO- phonon coupling but decreases with the temperature for weak exciton-LO-phonon coupling.