Spin dynamics of excited trion states in a single InAs quantum dot
Spin dynamics of excited trion states in a single InAs quantum dot
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DOI：
10.1103/physrevb.81.245304
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发表时间：
2010-06-04
影响因子：
3.7
通讯作者：
Arakawa, Y.
中科院分区：
文献类型：
--
作者：
Igarashi, Y.;Shirane, M.;Arakawa, Y.
我们测量了单个InAs/GaAs量子点（QD）的两条带正电荷的双激子发射线和一条带正电荷的激子发射线之间的光子互相关。观测到关联函数的显著差异，这源于中间态的多重自旋组态，即，激发带正电荷的激子（trion）态。借助于速率方程模拟，我们评估了p壳层空穴自旋翻转的跃迁速率为0.8-1.0 GHz，这几乎与接地带电激子的辐射衰减速率相当，这可能是由于量子点和润湿层中载流子之间的自旋散射和/或激发态的混合。与此相反，保守的p-壳层空穴自旋投影的弛豫速率估计为约一个数量级高于空穴自旋翻转。
We measure photon cross-correlation between two positively charged biexcitonic emission lines and a positively charged excitonic line for a single InAs/GaAs quantum dot (QD). Marked difference in the correlation function is observed, which originates from multiple spin configurations of intermediate states, i.e., excited positively charged exciton (trion) states. With the aid of a rate equation simulation, we evaluate the transition rate with p-shell hole-spin flip to be 0.8-1.0 GHz, which is almost comparable to the radiative decay rate of the ground charged exciton, presumably due to the spin scattering between carriers in a QD and a wetting layer and/or mixing of the excited trion states. In contrast, the relaxation rate with conserving p-shell hole-spin projection is estimated to be about one order of magnitude higher than that with hole-spin flip.