压电晶体中表面极化子的性质  

Properties of the Surface Polaron in Piezoeletric Crystals

作　　者：萨茹拉[1] 梁希侠[1] 

机构地区：[1]内蒙古大学物理系

出　　处：《内蒙古大学学报（自然科学版）》2003年第6期618-625,共8页Journal of Inner Mongolia University：Natural Science Edition

基　　金：国家自然科学基金资助课题(10164003)

摘　　要：研究了压电晶体中表面极化子的性质.首先用微扰法导出了压电晶体中表面极化子的有效哈密顿量,有效质量以及电子-表面声学声子作用的有效势,进而用变分法计算了表面态能量.研究结果指出:表面极化子的自陷能、有效势和有效质量不仅与压电常数、质量密度、声速、声子的德拜波数有关,而且也与电子至表面的距离有关.随着电子远离晶体表面,有效势、有效质量逐渐减小.压电晶体中电子-声学声子作用诱生的有效势是库仑型的,它使电子的能级降低,形成表面态.Some properties of a surface polaron in semiinfinite piezoelectric crystals are studied.The effective Hamiltonian,effective mass and effective potential of interaction between the electron and suface acoustic phonons for a surface polaron are derived by using a perturbation method and the surface state energy of an eletron is calculated by using a variationl approach.The results show that selftraping energy,effective potential and effective mass of surface polaron are related to the piezoeletric constant,mass density,sound velocity,Debye wave number and the distance from surface.The effective potential and effective mass decay when the electron goes away far from the surface.The effective potential from the interaction between the electron and the surface acoustic phonons is Coublomb potential.It lowers the surface state energy and forms surface states. 

关 键 词：压电晶体 表面极化子 表面态能量 

分 类 号：O471.3[理学—半导体物理]