Dynamics of coherent and incoherent spin polarizations in ensembles of quantum dots.
Dynamics of coherent and incoherent spin polarizations in ensembles of quantum dots.
复制标题
量子点集合中相干和非相干自旋极化的动力学。
DOI：
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发表时间：
2004
影响因子：
8.6
通讯作者：
M. Hopkinson
中科院分区：
文献类型：
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作者：
A. Tartakovskii;J. Cahill;M. N. Makhonin;D. Whittaker;J. Wells;A. M. Fox;D. Mowbray;M. S. Skolnick;K. Groom;M. Steer;M. Hopkinson
利用偏振分辨泵浦探测实验中观测到的量子拍频，得到了InGaAs量子点自旋相干性的温度依赖关系。在同一个样本中，我们清楚地区分了导致量子拍频的相干自旋动力学和非相干长寿命自旋记忆效应。使用理论模型对相干数据的分析揭示了与Borri等人先前在四波混合实验中对激子状态所发现的稳定性相比，高温下自旋相干性的稳定性大约高10倍[Phys.Rev.Lett. 87，157401（2001）]]。非相干极化的数据揭示了一种基于带电量子点的新型自旋存储器。
The temperature dependence of spin coherence in InGaAs quantum dots is obtained from quantum beats observed in polarization-resolved pump-probe experiments. Within the same sample we clearly distinguish between coherent spin dynamics leading to quantum beats and incoherent long-lived spin-memory effects. Analysis of the coherent data using a theoretical model reveals approximately 10 times greater stability of the spin coherence at high temperature compared to that found previously for exciton states in four-wave-mixing experiments by Borri et al. [Phys. Rev. Lett. 87, 157401 (2001)]]. The data on incoherent polarization reveal a new form of spin memory based on charged quantum dots.