厚度对磁场中抛物量子点内束缚极化子的影响

Thickness Effect on the Bound Polaron in a Parabolic Quantum Dot within a Magnetic Field

本文采用二级微扰方法研究厚度对抛物量子点内浅施主杂质处于磁场中极化子效应的影响。利用Ｌａｒｓｅｎ算符代数法描述系统在与磁场垂直平面内的运动而用电子局域波函数描述系统在与磁场平行方向的运动，得到系统的能级表达式以及基态能量二级微扰的ＬＯ声子极化效应。它们都是量子点局域强度，量子点厚度以及磁场强度的函数。同时，对ＧａＡｓ量子点作了数值计算。结果表明，量子点内浅施主基态能量在磁场中的极化子效应随磁场增强而增大，同时。

Thickness effect on the shallow donor in parabolic quantum dots within magnetic fields is investigated by using the second-order perturbation method. The motion of the system in the plane which perpendicular to the magnetic field is described by the Larsers operator algebra, and that of the motion in the direction which paralleled to the magnetic field is described by the electron confined wavefunction. The expressions of the energy levels of the system and the second-order pertubcton groundstate energy due to the polaronic effect of the LO phonon are obtained. They are functions of the confinement strength and the thickness of the quantum dots and the strength of the magnetic field. The case of the GaAs quantum dot is calculated numerically.The results show that the magnetic fields enhance the polaronic effect of the LO phonon to the shallow donors groundstate in quantum dot. And that the thickness of the quantum dot reduces the polaronic effect.