Structural analysis of strained quantum dots using nuclear magnetic resonance
Structural analysis of strained quantum dots using nuclear magnetic resonance
复制标题
DOI：
10.1038/nnano.2012.142
复制
发表时间：
2012-10-01
影响因子：
38.3
通讯作者：
Tartakovskii, A. I.
中科院分区：
文献类型：
--
作者：
Chekhovich, E. A.;Kavokin, K. V.;Tartakovskii, A. I.
应变半导体纳米结构可用于制造单光子源（1），检测器（2）和光伏器件（3），并可能用于创建量子逻辑器件（4，5）。这些应用的发展需要能够进行纳米级结构分析的技术，但通常用于分析这些材料的显微镜方法（6-8）是破坏性的。NMR技术可以提供非侵入性的结构分析，但是由于NMR光谱的显著应变诱导的四极加宽（12-14），NMR技术被限制于无应变半导体纳米结构（9-11）。在这里，我们表明，光学检测NMR光谱可以用来分析个别应变量子点。我们的方法使用连续波宽带射频激发，具有特殊设计的光谱图案，可以探测仅包含1x 10（5）四极核自旋的单个应变纳米结构。利用这种技术，我们能够测量单个受限电子所占据的体积中量子点的应变分布和化学成分。这种方法也可以用于解决量子信息处理中的问题，例如在强四极效应（18-21）存在的情况下精确控制核自旋（15-17）。
Strained semiconductor nanostructures can be used to make single-photon sources(1), detectors(2) and photovoltaic devices(3), and could potentially be used to create quantum logic devices(4,5). The development of such applications requires techniques capable of nanoscale structural analysis, but the microscopy methods(6-8) typically used to analyse these materials are destructive. NMR techniques can provide non-invasive structural analysis, but have been restricted to strain-free semiconductor nanostructures(9-11) because of the significant strain-induced quadrupole broadening of the NMR spectra(12-14). Here, we show that optically detected NMR spectroscopy can be used to analyse individual strained quantum dots. Our approach uses continuous-wave broadband radiofrequency excitation with a specially designed spectral pattern and can probe individual strained nanostructures containing only 1x10(5) quadrupole nuclear spins. With this technique, we are able to measure the strain distribution and chemical composition of quantum dots in the volume occupied by the single confined electron. The approach could also be used to address problems in quantum information processing such as the precise control of nuclear spins(15-17) in the presence of strong quadrupole effects(18-21).