Electron spin beats in InGaAs/GaAs quantum dots
Electron spin beats in InGaAs/GaAs quantum dots
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InGaAs/GaAs 量子点中的电子自旋节拍
DOI：
10.1134/1.1130874
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发表时间：
1999
影响因子：
0.6
通讯作者：
T. Amand
中科院分区：
文献类型：
--
作者：
V. Kalevich;M. N. Tkachuk;P. L. Jeune;X. Marie;T. Amand
首次利用时间分辨皮秒光谱研究了In（Ga）As/GaAs量子点阵列中载流子的光学取向和自旋动力学。发现由1.2 ps光脉冲产生的载流子在GaAs基质和润湿层中的光学取向和由QD捕获的光学取向持续几百皮秒。高激发光强下电子基态的饱和导致激发态电子极化接近100%，基态电子极化消失。首次在半导体量子点中观测到了横向磁场中的电子自旋量子拍。因此，我们确定In0.5Ga0.5As/GaAs量子点中的准零维电子因子为：|g| =0.27±0.03。
Time-resolved picosecond spectroscopy is used for the first time to study optical orientation and spin dynamics of carriers in self-organized In(Ga)As/GaAs quantum-dot (QD) arrays. Optical orientation of carriers created by 1.2 ps light pulses, both in the GaAs matrix and wetting layer, and captured by QDs is found to last a few hundreds of picosecond. The saturation of electron ground state at high-excitation-light intensity leads to electron polarization in excited states close to 100% and to its vanishing in ground state. Electron-spin quantum beats in a transverse magnetic field are observed for the first time in semiconductor QDs. We thus determine the quasi-zero-dimensional electrongfactor in In0.5Ga0.5As/GaAs QDs to be: |g⊥|=0.27±0.03.