库仑场对非对称量子点中强耦合极化子声子平均数的影响  

Influence of the Coulomb Field on the Mean Number of Phonons for Strong-coupling Polaron in an Asymmetric Quantum Dot

作　　者：许杰[1] 肖景林[2] 

机构地区：[1]辽东学院信息技术学院,辽宁丹东118003 [2]内蒙古民族大学物理与电子信息学院,内蒙古通辽028043

出　　处：《发光学报》2008年第3期547-550,共4页Chinese Journal of Luminescence

基　　金：国家自然科学基金资助项目(10347004,10747002)

摘　　要：采用线性组合算符和幺正变换方法研究库仑场对非对称量子点中强耦合极化子振动频率和声子平均数的影响。导出量子点中强耦合束缚极化子振动频率和声子平均数随量子点的横向和纵向有效受限长度,库仑束缚势和电子-声子耦合强度的变化关系。数值计算结果表明:非对称量子点中强耦合束缚极化子的振动频率和声子平均数随量子点的横向和纵向有效受限长度的减小而迅速增大。随库仑束缚势和电子-声子耦合强度的增加而增大。In the early 1980＇s, Tokuda studied the mean number of phonons for both the optical and the piezoelectric polarons within the scheme of variational approach based on the unitary transformation and the method of the Lagrange multiplier. Many investigators studied the properties of the mean number of phonons of polarons by using many methods. The properties of the mean number of phonons of the polaron in polar crystal, quantum well, quantum wire and symmetric quantum dot have been studied using the linear combination operator method by one of the present authors and co-worker. Recently, the mean number of phonon of the polaron in an asymmetric quantum dot has been calculated using linear combination operator method by the present author. However, using linear combination operator method, the properties of the mean number of phonons for the bound polaron in an asymmetric quantum dot has not been investigated so paper is to explore the effect of the transverse and the longitudinal effective dot, the Coulomb bound potential and the electron-phonon coupling strength far. The purpose of this present confinement length of quantum on the properties of strong-coupiing bound polaron in an asymmetric quantum dot. We obtain the expressions for the vibration frequency and the mean number of phonons of the strong-coupling bound polaron in an asymmetric quantum dot as a function of the transverse and the longitudinal effective confinement length of quantum dot, the Coulomb bound potential and the electron-phonon coupling strength by using linear combination operator and the unitary, transformation methods. Numerical calculations are performed and the results show that the vibration frequency and the mean number of phonons of the strong-coupling bound polaron in an asymmetries quantum dot will strongly increase with decreasing the transverse and longitudinal effective confinement length of quantum dot, and will increase with increasing the coulomb bound potential and the electron-phonon coupling strength.

关 键 词：非对称量子点 束缚极化子 声子平均数 线性组合算符 

分 类 号：O471.3[理学—半导体物理] O472.3[理学—物理]