量子点中极化子的内部激发态性质  

Properties of the Internal Excited State of the Polaron in Quantum Dot

作　　者：乌云其木格[1] 肖景林[1] 

机构地区：[1]内蒙古民族大学物理与机电学院,内蒙古通辽028043

出　　处：《发光学报》2007年第1期28-34,共7页Chinese Journal of Luminescence

基　　金：国家自然科学基金(10347004);内蒙自然科学基金(200208020110)资助项目

摘　　要：采用Huybrechts线性组合算符和幺正变换方法研究了抛物量子点中的强、弱耦合极化子的激发态性质。分别导出强、弱耦合情况下,抛物量子点中的极化子的第一内部激发态能量、激发能量、共振频率与量子点的有效受限长度和电子-声子耦合强度的关系。数值计算结果表明,量子点中弱耦合和强耦合极化子的内部激发态能量、激发能量和共振频率都随量子点的有效受限长度的减小而迅速增大。弱耦合极化子的第一内部激发态能量随电子-声子耦合强度的增加而减少;而强耦合极化子的振动频率随量子点的有效受限长度的减小而迅速增加。弱耦合极化子的第一内部激发态能量、激发能量和共振频率随电子-声子耦合强度的增加而减小。： The properties of the excited state of the weak- and strong-coupling polaron in a parabolic quantum dot were studied by using the Huybrechts＇ linear combination operator and the unitary transformation method. The first internal excited state energy, the excitation energy and the resonance frequency of both the strongand weak-coupling polaron in a parabolic quantum dot are derived respectively. First, we have investigated the properties of the excited state energy, the excitation energy and the resonance frequency of the weak-coupling polaron in a paraboli state energy with the effective confinement length of the c quantum dot. The relation of both the excited quantum dot and the electron-phonons coupling strength and the excitation energy and the resonance frequency with the effective confinement length of the quantum dot. The results show that, the excited state energy will increase strongly with decreasing the effective confinement length of the quantum dot, and will increase with decreasing the electron-phonon coupling strength, and the excitation energy and the resonance frequency increase with decreasing the effective confinement length of the quantum dot. Second, the properties of the vibrational frequency, the excited state energy, the excitation energy and the resonance frequency of the strong-coupling polaron in a parabolic quantum dot are studied. The relation of these quantities with the effective confinement length of the quantum dot, and the electron-phonon coupling strength is discussed. The results show that, the internal excited state energy, the excitation energy and the resonance frequency will increase strongly with decreasing the effective confinement length of the quantum dot, and increase with decreasing the electron-phonon coupling strength, and the vibrational frequency increase with decreasing the effective confinement length and increase with increasing the electron-phonons coupling strength.

关 键 词：抛物量子点 强 弱耦合 极化子 第一内部激发态能最 

分 类 号：O471.4[理学—半导体物理] O472.3[理学—物理]