非对称高斯势二能级体系的跃迁频率和自发辐射率

Transition Frequency and Spontaneous Emission Rate in the Asymmetric Gaussian Potential Two-Level System

采用Pekar变分法研究了双参量非对称高斯势二能级体系中电子态的概率密度、跃迁频率及体纵光学声子自发辐射率,并讨论了其单参量抛物势近似。数值结果表明:选用双参量非对称高斯势描写量子点中电子的受限效应能够更恰当地反映电子态的波动性、电子运动的统计规律性及声子自发辐射率的量子化特性,而其单参量抛物势近似给出的结果较为简单和粗糙。材料的色散及电声耦合对二能级体系中电子态的概率分布、量子跃迁频率和体纵光学声子自发辐射率的影响不能忽略。

The probability density, the transition frequency and the longitudinal optical(LO) phonon spontaneous emission rate of electronic states in the two-parameter asymmetric Gaussian(AG) potential two-level system are studied by using the Pekar variational method, and their single-parameter parabolic potential approximation are discussed. Numerical results show that the selecting the two-parameter AG potential to describe the restricted effects of electron in quantum dot can more accurately reveal the quantization characteristics of the wave property of electronic states, the statistical regularity of electron motion and the LO phonons spontaneous emission rate, and the results given by the single parametric parabolic approximation are relatively sample and rough. The influence of dispersion and electron-phonon coupling of materials on the probability distribution, quantum transition frequency and the LO spontaneous emission rate in the two-level system cannot be ignored.