半无限晶体中慢速运动的表面极化子

本文研究电子与体纵光学声子耦合弱、与表面光学声子耦合强的半无限晶体中的表面极化子的性质.采用改进了的线性组合算符法和微扰法导出了半无限晶体中的慢速运动极化子的有效哈密顿量.在计及电子在反冲效应中发射和吸收的不同波矢的声子之间的相互作用时,讨论了对有效哈密顿量,诱生势和有效质量的影响.对AgBr晶体进行了数值计算,结果表明反冲效应中发射和吸收的不同波矢的声子之间的相互作用对有效质量和诱生势的影响随耦合常数αt的增加而增加,对有效质量的影响随坐标z的增加而减小的更多,对诱生势的影响随z的增加而增加的更多.

PROPERTY OF SLOW MOVING SURFACE POLARON IN A SEMI-INFINITE CRYSTAL

In this paper,the properties of the surface polaron,which is a weak bulk couplingbut a strong surface coupling between the electron and phonon for semi-infinite crystalare sttldied.An effective Hamiltonian of a slow moving surface polaron is derived byusing improved liner combination operator and perturbation method.In the recoil proprocess of an electron,the electron will emit or absorb phonons.Considering the interaction of phonons with different wave vector,the influence of this interaction on the effective Hamiltonian,the induced potential,and the effective mass of surface polaron arediscussed.As an example,the numerical calculation for AgBr crystal has been carried.The results show that the influence of the interaction between phonons of different wavevector in the recoil process on the effective mass and induced potential will be increasedwith increasing coupling constant α1,and the influence on the effective mass will be decreased more with increasing coordinate z,and influence on the induced potential will beincreased more with increasing z.