Tuning of g -factor in self-assembled In(Ga)As quantum dots through strain engineering
Tuning of g -factor in self-assembled In(Ga)As quantum dots through strain engineering
复制标题
DOI：
10.1103/physrevb.71.205301
复制
发表时间：
2005-05
影响因子：
3.7
通讯作者：
T. Nakaoka;Toshio Saitô;J. Tatebayashi;S. Hirose;Tatsuya Usuki;N. Yokoyama;Y. Arakawa
中科院分区：
文献类型：
--
作者：
T. Nakaoka;Toshio Saitô;J. Tatebayashi;S. Hirose;Tatsuya Usuki;N. Yokoyama;Y. Arakawa
我们已经调查的$g$-因子的自组装In（Ga）As点的单点光谱和八带的有效质量计算考虑到应变分布和塞曼效应的影响应变的影响。通过热退火或通过引入应变减小层来改变量子点中及其周围的应变及其分布。热退火产生一个渐变的组合物的配置文件由于$\mathrm{In} xiao\mathrm{Ga}$混合。梯度组成分布降低了点底部附近的流体静力学和双轴向应变，并增强了顶部附近的流体静力学和双轴向应变。这种应变的变化导致在一个大的减少的绝对空穴$g$-值和一个小的减少的绝对电子$g$-值。另一方面，在InAs点上覆盖一层0.17 Ga 0.83 As应变减小层，主要是减小了流体静力应变。应变的变化和带边的排列增强了电子的g值，同时降低了空穴的g值。这些结果应提供见解，以控制金字塔自组装点的$g$-因素。
We have investigated the effect of strain on the $g$-factors of self-assembled In(Ga)As dots by single-dot spectroscopy and an eight-band effective mass calculation taking into account the influence of the strain distribution and the Zeeman effect. The strain and its distribution in and around the quantum dots are varied by thermal annealing or by introducing an strain reducing layer. Thermal annealing produces a graded composition profile due to $\mathrm{In}\mathrm{Ga}$ intermixing. The graded composition profile reduces both hydrostatic and biaxial strain near the bottom of the dot, and enhances them near the top. This strain variation results in a large reduction of the absolute hole $g$-value and a small reduction of the absolute electron $g$-value. On the other hand, the covering of InAs dots with an ${\mathrm{In}}_{0.17}{\mathrm{Ga}}_{0.83}\mathrm{As}$ strain reducing layer decreases mainly the hydrostatic strain. The variation of the strain and the band edge alignment enhance the electron $g$-value while they reduce the hole $g$-value. These results should provide insights to control the $g$-factors in pyramidal self-assembled dots.