Direct observation of relaxation dynamics of spin-polarized electrons excited at a higher-energy spin-split subband in a diluted magnetic semiconductor quantum well
Direct observation of relaxation dynamics of spin-polarized electrons excited at a higher-energy spin-split subband in a diluted magnetic semiconductor quantum well
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DOI：
10.1063/1.2753091
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发表时间：
2007-06
影响因子：
4
通讯作者：
Kyosuke Saito;Jiho Park;I. Souma;Y. Oka;A. Murayama
中科院分区：
文献类型：
--
作者：
Kyosuke Saito;Jiho Park;I. Souma;Y. Oka;A. Murayama
利用泵浦-探测吸收光谱技术，观察了稀磁半导体量子阱中高能自旋分裂子带激发的自旋极化电子的驰豫动力学。圆偏振饱和吸光度的时间依赖关系直接反映了自旋极化电子的驰豫，这是光致发光所不能达到的。在2.5T的吸收带内，获得了2~100ps的驰豫时间与探测能量的关系。这种依赖关系被自旋极化电子的带内能量弛豫和随后的激子局域化效应修正的电子-自旋弛豫所系统地解释。
The authors observe relaxation dynamics of spin-polarized electrons excited at a higher-energy spin-split subband in a diluted magnetic semiconductor quantum well by means of pump-probe absorption spectroscopy. Time dependences of the circularly polarized saturated absorbance directly show the relaxation of spin-polarized electrons, which is inaccessible by photoluminescence. The probe-energy dependence of the relaxation time is obtained ranging from 2to100ps at 2.5T within the absorption band. This dependence is systematically explained by both the intraband energy relaxation of the spin-polarized electrons and the subsequent electron-spin relaxation that is modified by effects of the exciton localization.