流体静压力下磁场对半导体异质结中束缚极化子的影响

对GaAs/AlxGa1-xAs半导体异质结系统,引入实际异质结势,同时考虑体纵光学(LO)声子和两支界面光学(IO)声子的影响,采用变分法讨论了外界磁场和压力对束缚极化子的影响.利用改进的Lee-Low-Pines(LLP)中间耦合方法处理电子-声子和杂质-声子的相互作用,计算了束缚极化子结合能随压力、磁场强度、杂质位置的变化关系.结果表明,结合能和声子对结合能的贡献随压力和磁场强度的增加而增大.磁场对于IO声子和LO声子对结合能贡献的影响是非线性的,而压力对二者的影响均是近线性的,且磁场和压力对LO声子的作用更为显著.

Magnetic Field Effect on Bound Polarons in Semiconductor Heterojunctions under Hydrostatic Pressure

A realistic heterojunction potential model is adopted to discuss magnetic field and hydrostatic pressure effects on a bound polaron near a GaAs/AlxGa1-x As semiconductor heterojunction interface by considering the longitudinal optical (LO) phonons and two branches of interface optical (IO) phonons. A modified Lee-Low-Pines (LLP) method is used to deal with the electron-phonon and impurity-phonon interactions. The binding energies of bound polarons as functions of pressure,magnetic field and impurity position are obtained. The results show that the binding energy and the contribution of phonons to the binding energy increase with pressure and magnetic field. The influences of magnetic field on the contributions of the IO phonons and the LO phonons are nonlinear whereas the pressure influences on the both are nearly linear. The magnetic and pressure effects on the LO phonons are more obvious.