Cross calibration of deformation potentials and gradient-elastic tensors of GaAs using photoluminescence and nuclear magnetic resonance spectroscopy in GaAs/AlGaAs quantum dot structures
Cross calibration of deformation potentials and gradient-elastic tensors of GaAs using photoluminescence and nuclear magnetic resonance spectroscopy in GaAs/AlGaAs quantum dot structures
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DOI：
10.1103/physrevb.97.235311
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发表时间：
2018-06-19
影响因子：
3.7
通讯作者：
Rastelli, A.
中科院分区：
文献类型：
--
作者：
Chekhovich, E. A.;Griffiths, I. M.;Rastelli, A.
在T = 4.2 K下，研究了晶格匹配的GaAs/AlGaAs量子点外延结构在沿着[001]或[110]晶向静态单轴应力作用下的性能。我们进行同步测量的光谱位移的块状GaAs衬底的光致发光，这涉及到应变通过变形势a和B，和四极位移的量子点，这涉及到相同的应变通过梯度弹性张量S-ijkl的光学检测的核磁共振光谱。在两个单轴应力配置的测量被用来推导出的比值B/a = 0.242 +/- 0.008与以前的研究GaAs的良好协议。基于先前估计的近似为-8.8eV的值，我们推导出GaAs中的核四极矩Q与S张量对角分量的乘积，对于As-75为QS（11）近似为+0.758x10（-6）V，对于Ga-69为QS（11）近似为-0.377x10（-6）V。在我们的实验中，S u的符号是直接可测量的，这在早期的核声共振研究中是不可能的。我们的QS（11）值比核声共振实验[Phys. Rev. B 10，4244（1974）]得出的值小约1.4倍。在这项工作中测量的梯度弹性张量值可以应用于应变III-V族半导体纳米结构的结构分析，通过精确建模其磁共振谱。
Lattice matched GaAs/AlGaAs epitaxial structures with quantum dots are studied at T = 4.2 K under static uniaxial stress applied either along the [001] or [110] crystal directions. We conduct simultaneous measurements of the spectral shifts in the photoluminescence of the bulk GaAs substrate, which relate to strain via deformation potentials a and b, and the quadrupolar shifts in the optically detected nuclear magnetic resonance spectra of the quantum dots, which relate to the same strain via the gradient-elastic tensor S-ijkl. Measurements in two uniaxial stress configurations are used to derive the ratio b/a = 0.242 +/- 0.008 in good agreement with previous studies on GaAs. Based on the previously estimated value of a approximate to -8.8 eV we derive the product of the nuclear quadrupolar moment Q and the S-tensor diagonal component in GaAs to be QS(11)approximate to +0.758 x 10(-6) V for As-75 and QS(11) approximate to -0.377 x 10(-6) V for Ga-69 nuclei. In our experiments the signs of S u are directly measurable, which was not possible in the earlier nuclear acoustic resonance studies. Our QS(11) values are a factor of similar to 1.4 smaller than those derived from the nuclear acoustic resonance experiments [Phys. Rev. B 10, 4244 (1974)]. The gradient-elastic tensor values measured in this work can be applied in structural analysis of strained III-V semiconductor nanostructures via accurate modeling of their magnetic resonance spectra.