量子阱中的双极化子

Properties of Bipolaron in a Quantum Well

在同时考虑电子与ＬＯ声子及ＩＯ声子相互作用的情况下，用ＬＬＰ正则变换的方法研究了半导体量子阱中双极化子的性质．给出了由于电子－ＬＯ声子及电子－ＳＯ声子相互作用而产生的诱生势，并且以ＧａＡｓ／Ａｌ０．３Ｇａ０．７Ａｓ为例进行了数值计算．通过计算可得出如下结论：（１）双极化子的诱生势可以分为两部分，其中一部分仅与一个电子的坐标ｚ１（ｚ２）有关，另一部分则不仅与两个电子的坐标ｚ１和ｚ２都有关，还与两个电子间的相对距离ρ有关；（２）诱生势ＶＩＬ（ρ）和ＶＩ，σ（ρ）的绝对值随着双极化子中两个电子间相对距离ρ的增加而减小；（３）由于电子与ＩＯ声子相互作用而产生的诱生势ＶＩ，σ（ρ）的绝对值随量子阱宽度Ｎ的增加而减小．

The interactions of the electron with both the bulk longitudinal optical (LO) phonon and the interface optical (IO) phonon were used to derive the expressions of the induced potentials. And the LLP variational method was employed. The numerical calculations of the induced potentials for GaAs/Al 0.3 Ga 0.7 As, as an example, were made. From the calculations, it can draw the conclusions:① The interaction potentials induced by the interaction of phonons with the electron can be divided into two parts. One is only relevant to the coordinate z 1(z 2) , and the other is relevant not only to z 1 and z 2 but also to ρ . ② The absolute values of the induced potentials V IL (ρ) and V I, σ (ρ) decrease with the increase of ρ . ③ The absolute value of IO phonon induced potential decreases with the increase of the quantum well width. The method used in this paper is suitable to both weak coupling and intermediate coupling systems.