Optically monitored nuclear spin dynamics in individual GaAs quantum dots grown by droplet epitaxy
Optically monitored nuclear spin dynamics in individual GaAs quantum dots grown by droplet epitaxy
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DOI：
10.1103/physrevb.78.205325
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发表时间：
2008-11-01
影响因子：
3.7
通讯作者：
Urbaszek, Bernhard
中科院分区：
文献类型：
--
作者：
Belhadj, Thomas;Kuroda, Takashi;Urbaszek, Bernhard
我们报告的光学取向实验在个别应变的GaAs量子点在AlGaAs生长液滴外延。圆偏振光激发在4K下产生强烈的光致发光圆偏振。将自旋极化的电子光学注入到点中会引起动态核极化，从而大大改变激子塞曼分裂（Overhauser位移）。我们发现，所产生的核极化是100，我们提出了一个直接测量的建立时间的核极化在一个单一的GaAs点在1秒的顺序。
We report on optical orientation experiments in individual strain-free GaAs quantum dots in AlGaAs grown by droplet epitaxy. Circularly polarized optical excitation yields strong circular polarization of the resulting photoluminescence at 4 K. Optical injection of spin-polarized electrons into a dot gives rise to dynamical nuclear polarization that considerably changes the exciton Zeeman splitting (Overhauser shift). We show that the created nuclear polarization is bistable and we present a direct measurement of the buildup time of the nuclear polarization in a single GaAs dot in the order of 1 s.