声子色散和库仑势对量子点中极化子基态能量的影响(英文)  

Influence of phonon dispersion and the coulomb potential on the ground state energy of polaron in a quantum dot

作　　者：李伟萍[1] 肖景林[2] 

机构地区：[1]内蒙古赤峰学院物理与电子信息系,赤峰024000 [2]内蒙古民族大学物理与电子信息学院,通辽028043

出　　处：《原子与分子物理学报》2010年第5期949-953,共5页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10747002);内蒙古高校基金(NJzc08158)

摘　　要：本文在声子色散和库仑束缚势的影响下利用压缩态变分法计算了抛物量子点中弱耦合极化子的基态能量.采用的变分方法是基于逐次正则并且利用单模压缩态变换处理通常被我们所忽略的在第一次幺正变换中产生的声子产生湮灭算符的双线性项.计算得出了在考虑声子色散和库仑束缚势的情况下抛物量子点中弱耦合极化子的基态能量的数学表达式.讨论了在弱耦合情况下,受限长度,电子-声子耦合常数,色散系数,库仑结合参数与基态能量之间的依赖关系.The ground state energy of weaking-coupling polaron in a parabolic quantum dot considering the phonon dispersion and the Coulomb bound potential is calculated using the squeezed-state variational approach. The variational approach we applied is based on two successive canonical transformations and using a single-mode squeezed-state type unitary transformation to deal with the bilinear terms which we neglected usually. Considering the phonon dispersion and Coulomb bound potential, the ground state energy of weak- coupling polaron in a parabolic QD is calculated. The relations on the ground-state energy of bound polaron in a parabolic quantum dot with the electron-LO-phonon coupling constant, the coefficient of phonon dispersion, the Coulomb binding parameter and the confinement length are derived in the electron-LO-phonon weak-coupling case.

关 键 词：声子色散 压缩态 量子点 束缚极化子 

分 类 号：O471.3[理学—半导体物理] O472.3[理学—物理]