Excitation energy dependence of initial phase shift in Kerr rotation of resident electron spin polarization in a CdTe single quantum well
Excitation energy dependence of initial phase shift in Kerr rotation of resident electron spin polarization in a CdTe single quantum well
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CdTe 单量子阱中驻留电子自旋极化克尔旋转初始相移的激发能量依赖性
DOI：
10.1002/pssb.201600449
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
and S. Adachi
中科院分区：
文献类型：
--
作者：
L.-P. Yan;T. Takamure;R. Kaji;G. Karczewski;S. Takeyama;and S. Adachi
驻留电子自旋极化的生成动力学涉及取决于激发光子能量的相关光激发态的形成和转变。驻留电子自旋极化进动的初始相移为揭示相关激发态和驻留电子之间的相互作用提供了重要线索。在这项工作中，在低磁场下的 CdTe/CdMgTe 单量子阱中研究了驻留电子自旋极化的克尔旋转初始相移的激发能量依赖性。通过对自旋进动的仔细分析，当激发能量增加超过中性激子共振时，激发的电子-重空穴对表现出独特的自旋动力学。同时，负初始相移的幅度变得非常大。较大的初始相移和独特的进动轨迹是由中性激子到负三子的转变以及伴随的空穴自旋翻转引起的。实验估计激子到三重子的转变时间为 160ps。
The generation dynamics of a resident electron spin polarization involve the formation and transformation of the associated optically excited states depending on the excitation photon energy. Initial phase shift in the precession of a resident electron spin polarization gives the important clues to reveal the interplay between the associated excited states and resident electrons. In this work, the excitation energy dependence of the initial phase shift in Kerr rotation of a resident electron spin polarization is investigated in a CdTe/CdMgTe single quantum well under a low magnetic field. Through the careful analysis of the spin precession, the excited electron–heavy‐hole pairs show unique spin dynamics when the excitation energy is increasing past the neutral exciton resonance. Meanwhile, the negative initial phase shift becomes significantly large in magnitude. The larger initial phase shift and the unique precession traces are caused by the transformation from neutral excitons to negative trions with accompanying the hole spin‐flip. The exciton‐to‐trion transformation time is estimated experimentally to be 160 ps.