Measurement of heavy-hole spin dephasing in (InGa)As quantum dots
Measurement of heavy-hole spin dephasing in (InGa)As quantum dots
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DOI：
10.1063/1.3678182
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发表时间：
2012-01-16
影响因子：
4
通讯作者：
Oestreich, M.
中科院分区：
文献类型：
--
作者：
Dahbashi, R.;Huebner, J.;Oestreich, M.
我们通过自旋噪声光谱测量了自组装 (InGa)As 量子点中局域空穴的自旋相移。尽管价带态具有 p 型对称性，但局部空穴仍显示出与核自旋浴的明显超精细相互作用。实验揭示了 27 ns 的短自旋弛豫时间 tau(hh)（快）和第二个长自旋弛豫时间 tau(hh)（慢），超过后者一个数量级以上。这两次归因于垂直和平行于随机核磁场的重空穴自旋。强度相关测量和数值模拟表明，尽管激光强度较低且失谐较大，但长弛豫时间仍然被光吸收所掩盖。由于第二个空穴的产生导致空穴自旋极化消失，非共振光吸收导致自旋噪声信号的抑制。 (C) 2012 年美国物理研究所。 [doi:10.1063/1.3678182]
We measure the spin dephasing of holes localized in self-assembled (InGa)As quantum dots by spin noise spectroscopy. The localized holes show a distinct hyperfine interaction with the nuclear spin bath despite the p-type symmetry of the valence band states. The experiments reveal a short spin relaxation time tau(hh)(fast) of 27 ns and a second, long spin relaxation time tau(hh)(slow) which exceeds the latter by more than one order of magnitude. The two times are attributed to heavy-hole spins aligned perpendicular and parallel to the stochastic nuclear magnetic field. Intensity dependent measurements and numerical simulations reveal that the long relaxation time is still obscured by light absorption, despite low laser intensity and large detuning. Off-resonant light absorption causes a suppression of the spin noise signal due to the creation of a second hole entailing a vanishing hole spin polarization. (C) 2012 American Institute of Physics. [doi:10.1063/1.3678182]