Model for the coherent optical manipulation of a single spin state in a charged quantum dot
Model for the coherent optical manipulation of a single spin state in a charged quantum dot
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DOI：
10.1103/physrevb.77.115347
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发表时间：
2008-03
影响因子：
3.7
通讯作者：
G. Slavcheva
中科院分区：
文献类型：
--
作者：
G. Slavcheva
利用新的Maxwell赝自旋模型，研究了嵌入实际结构中的带电半导体量子点中局域自旋的单次初始化和读出过程中的光驱动相干动力学.本文导出了广义赝自旋主方程，用包含自旋弛豫过程耗散的真实的态赝自旋相干矢量来描述自旋相干态和自旋布居数随时间的演化。该方程是在时域中求解的矢量麦克斯韦方程组的耦合到它通过宏观介质的偏振光波传播自洽。使用该模型，长寿命的电子自旋相干性留下一个单一的共振超短光激发的电子-三振子跃迁的带电量子点在低强度和高强度拉比振荡制度进行了模拟。偏振光致发光PL从数值模拟，如第二回波脉冲的外观后的激励和一个特性的非单调的PL迹线形状，具体的初始自旋方向，产生的签名进行了讨论，实现高保真度计划的相干读出一个单一的自旋偏振态。
The optically driven coherent dynamics associated with the single-shot initialization and readout of a localized spin in a charged semiconductor quantum dot embedded in a realistic structure is theoretically studied using a new Maxwell-pseudospin model. Generalized pseudospin master equation is derived for description of the time evolution of spin coherences and spin populations in terms of the real state pseudospin coherence vector including dissipation in the system through spin-relaxation processes. The equation is solved in the time-domain self-consistently with the vector Maxwell equations for the optical wave propagation coupled to it via macroscopic medium polarization. Using the model, the long-lived electron spin coherence left behind a single resonant ultrashort optical excitation of the electron-trion transition in a charged quantum dot is simulated in the low- and high-intensity Rabi oscillation regime. Signatures of the polarized photoluminescence PL resulting from the numerical simulations, such as the appearance of a second echo pulse following the excitation and a characteristic nonmonotonic PL trace shape, specific for initial spin-up orientation, are discussed for realization of high-fidelity schemes for coherent readout of a single spin polarization state.