纤锌矿准一维GaN/Al_xGa_(1 -x)N量子阱线中的极化准受限光学声子模(英文)

Polar Quasi-Confined Optical Phonon Modes in Wurtzite Quasi-One-Dimensional GaN/Al_xGa_(1-x)N Quantum Well Wires

基于介电连续模型与Loudon的单轴晶体模型,推导分析了纤锌矿准一维量子阱线中的准受限( QC)光学声子模及相应的电子-QC光学声子之间的相互作用函数.对一个Al N/GaN/Al N纤锌矿量子阱线进行了数值计算.结果显示,当体系的角量子数m与z方向上的自由波数kz较小时,QC光学声子模的色散相当明显.观察到纤锌矿量子体系中的QC光学声子模的“退化”行为.通过电子-QC光学声子之间的耦合函数的讨论发现,高频区中的低频支QC模在电子-QC光学声子模之间的相互作用中起主要作用.计算结果还证明自由波数kz与角量子数m对电子-QC光学声子模间的耦合特性具有相似的影响.

Based on the dielectric continuum model and Loudon＇s uniaxial crystal model,quasi-confined （QC） optical phonon modes and electron-QC phonon coupling functions in quasi-one-dimensional （QID） wurtzite quantum well wires （QWWs） are deduced and analyzed. Numerical calculations on an AIN/GaN/AIN wurtzite QWW are performed. The results reveal that the dispersions of the QC modes are quite obvious only when the free wavenumber kz in the z-direction and the azimuthal quantum number m are small. The reduced behavior of the QC modes in wurtzite quantum systems is clearly observed. Through the discussion of the electron-QC mode coupling functions,it is found that the lower-frequency QC modes in the high-frequency region play a more important role in the electron-QC phonon interactions. Moreover,our computations also prove that kz and m have a similar influence on the electron-QC phonon coupling properties.