中文摘要：

利用改进的Lee-Low-Pines（LLP）方法和变分法研究了在外磁场作用下氮化物无限抛物量子阱中自由极化子的能级，得到了极化子基态能量随量子阱阱宽和外磁场变化的规律，对GaN/Al0. 3 Ga0.7 N抛物量子阱进行了数值计算。结果表明：外磁场对极化子的能量有明显的影响，极化子基态能量随阱宽的增强而减小，随磁场的增强而增大，并且电子一声子相互作用对氮化物量子阱中极化子能量的贡献是很大的。

英文摘要：

Recent advances in semiconductor optoelectronics and electronics based on wide band-gap nitride materials have resulted in substantial interest in the basic properties of wurtzite crystals. Particularly, acomplete understanding of carrier-phonon interaction mechanisms and rates is essential to further progress in these fields. There are many more distinct phonon branches （ nine optical and three acoustic modes） in wurtzite mate- rials. At the same time the phonon modes may not be purely longitudinal nor transverse modss. Since B. C. Lee presents a theory of electron-optical-phonon interaction in uniaxial crystals of wurtzite type based on the macroscopic dielectric continuum model and the uniaxiaal models, the special properties of superlattice and heterostructure have been investigated by many persons. However the effect of the external magnetic field on the nitride parabolic quantum well materials, to our knowledge, have rarely been investigated. In this paper, the energy the external magnetic field is changing with the width of the level of a free polaron in a nitride infinite parabolic quantum well as function of studied using the LLP variational method. The ground state energy of polaron quantum well and the external magnetic fields are obtained. Our numerical resuits for a GaN/Al0.3 Ga0.7 N parabolic quantum well show that the effects of the external magnetic fields on the ground state enerygy are very obvious. The energy of the polaron decrease with increasing well width and increase with increasing magnetic fields strength. At the same time, the contribution of the interaction between the electron and phonon to the energy of polaron in the nitride parabolic quantum well is noticeable.