有限深量子阱中极化子束缚能

Polaron Binding Energy in a Finite-barrier Quantum Well

本文用改进的Ｌｅｅ－Ｌｏｗ－ｐｉｎｅｓ变分法研究了界面光学声子，局域体光学声子以及半无限体光学声子对有限深量子阱中极化子束缚能的影响，得到了电子束缚态能量和极化子束缚能的解析表达式，该表达式可用于任意宽度的量子阱，并给出正确的二维和三维极限。本文对ＧａＡｓ／Ｇａ＿（１－ｘ）Ａｌ＿ｘＡｓ量子阱作了具体数值计算，给出了计算结果。还分析和讨论了各种声子模对极化子束缚能的贡献，以及量子阱中极化子的一些特征。

The effects of the interface optical phonons and the confined longitu-dinal optical phonons as well as the half-space longitudinal optical phonons on the binding energy of a polaron in a finite-barrier quantum well are investigated by us-ing a modified Lee-low-Pines variation method.The analytical expressions for the bound state energy and the binding energy of the polaron are obtained ,which can be applied to a wide range of the well width, and the correct three-dimensional and two-dimensional results are given as limit cases.The numerical results of the bind-ing energies are fraphically shown as functions of the well width for the GaAs/ Ga_1-_zAl_zAs quantum wells with several Al concentrations. The contributions of different kinds of phonon modes to the polaron binding energy are clearly shown and analyzed. Some interesting features of the polaron are found.