外加磁场下类氢施主杂质量子点中的激子

黄锦胜，林少光，林凯燕，陈国贵



外加磁场下类氢施主杂质量子点中的激子

黄锦胜，林少光，林凯燕，陈国贵

（揭阳职业技术学院 师范教育系，广东 揭阳 522051）

利用精确对角化方法计算了外加磁场下类氢施主杂质量子点中的激子的束缚能，发现系统的束缚能随着量子点的束缚势的增大而减小，随着外加磁场的增大而减小.

类氢施主杂质；量子点；磁场；束缚能

1 理论推导

引入二维谐振子波函数乘积基：

2 计算结果和讨论

本文着重考查束缚态的存在会受到哪些条件的影响. 参照文献[17]束缚能表示为

其中，是杂质系统激子的本征能量，是空穴在抛物势量子点中的最低能量，其不受库仑势作用，是杂质束缚着电子的基态能. 从式(6)可以看出，束缚能就是把空穴从杂质系统内激子的束缚态中分离出来，成为在量子点中具有基态能为的单粒子态所需的最低能量. 当时，激子在杂质系统存在束缚态.

图2 施主杂质系统中激子基态能和电子基态能随束缚势大小的变化关系

图3 施主杂质系统中激子基态(L=0)和第一激发态(L=1)束缚能随外加磁场大小的变化关系

图4 施主杂质系统中激子基态束缚能随电子空穴质量比大小的变化关系

3 结论

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[责任编辑：韦 韬]

Exciton of a Hydrogenic Donor Quantum Dot in a Magnetic Fields

HUANGJin-sheng, LINShao-guang, LINKai-yan, CHENGuo-gui

(Department of Normal-education, Jieyang Vocational Technology College, Jieyang 522051, China)

An investigation of binding energy of a hydrogenic donor in a parabolic quantum dot with exciton under magnetic field is calculated by using the matrix diagonalization method. The results indicate that the binding energy decreases with increasing confinement strength and also decreases with increasing the magnetic field strength.

Hydrogenic donor; Quantum dot; Magnetic field; Binding energy

1006-7302（2013）01-0050-05

O474

A

2012-10-09

揭阳职业技术学院重点资助项目（JYCKZ1102）

黄锦胜（1980—）, 男，广东梅州人, 讲师，硕士，主要从事低维半导体材料光学性质研究.