库仑场下三角量子阱中弱耦合极化子的相互作用能

Influence of the Coulomb Field on Interaction Energy of Weak-coupling Bound Polaron in a Triangular Quantum Well

本文在Huybrechts弱耦合极化子模型的基础上,采用线形组合算符和两次幺正变换相结合的方法研究了库仑场下各种量对三角量子阱中弱耦合极化子相互作用能的影响。经过推导,得出了三角量子阱中弱耦合极化子相互作用能的表达式,库仑场下三角量子阱中弱耦合极化子相互作用能由三项组成:分别包括束缚势能量、电子与体纵光学声子之间相互作用能和三角量子阱中限制势能量。这三个部分对相互作用能各有贡献,均不可忽略。进一步还可以选择具体的半导体材料进行数值计算,从而得到确定半导体量子阱中极化子相互作用能随量子阱中库仑束缚势、电子-声子耦合强度和三角量子阱中限制势的数值对应变化关系,从而体会库仑场下各种参量对三角量子阱中弱耦合极化子奇特的量子效应。此结论也可以广泛推广到库仑场下各种弱耦合材料三角量子阱中极化子相互作用能的参考和计算。

With the rapid development of semiconductor material production technology,it has become possible to make of kinds of quantum wells.Due to the different structures of quantum wells,some physical properties such as optical characteristics are quite different from those of the bulk materials.There has been a great interest in investigation quantum wells both theoretically and experimentally.The problem of a polaron with the longitudinal optical phonon field of a polar semiconductor draw physicists’attention,has been maintained over years.Many investigators studied the properties of polaron in a quantum well in many aspects by a variety of methods.Recently,the properties of polaron in a triangular quantum well have been studied using the linear combination operator and the unitary transformation methods.The influence of the Coulomb field on the properties of polaron in a triangular quantum well has not been fully investigated so far.In this paper,On the basis of Huybrechts’weak-coupling polaron model,the linear-combination operator method and the unitary transformation method were used to study the properties of the weak-coupling bound polaron,in a semiconductor triangular quantum well.The expressions for the interaction energy of the polaron as a function of the Coulomb bound potential,the coupling constant and the electron areal density were derived.The interaction energy of the weak-coupling polaron in triangular quantum well is composed of three parts:Coulomb bound potential,the coupling constant energy and the triangular potential.The contribution of these three parts to the interaction energy cannot be ignored.Furthermore,to show more clearly the effect of the these parts,we choose specific semiconductor materials for numerical calculation to obtain the relationship between the interaction energy and the Coulomb bound potential,the electron-phonon coupling strength and the confinement potential in the triangular quantum well.This conclusion can be extended to the reference and calculation of the polaron interaction energy in various weak-coupling materials of Triangular quantum wells considering an influence of Coulomb field.The method and results in this paper are applicable to the ground state of the electron-phonon coupling system in a triangular quantum well,when the electron-phonon coupling constant less than 3,the temperature is lower than the Debye Temperature.