论文标题
在自组装量子点分子的最佳位置增强了自旋连贯性
Enhanced spin coherence at the sweet spot of a self-assembled quantum dot molecule
论文作者
论文摘要
在每个点中，一对带有一个电子的耦合点可以提供自旋连贯性的改善，尤其是在称为甜点的电偏见下，但是在此制度中，对自组装点的测量很少。在这里，我们直接测量了该系统中单线三态的$ T_2^*$相干时间，这是偏置和磁场的函数，获得了60 ns的最大$ T_2^*$，比单个量子点中的电子旋转高的数量级。我们的结果发现了两种主要的去向物机制：远离甜点的电噪声，以及由于G因子的差异而与核自旋相互作用。
A pair of coupled dots with one electron in each dot can provide improvements in spin coherence, particularly at an electrical bias called the sweet spot, but few measurements have been performed on self-assembled dots in this regime. Here, we directly measure the $T_2^*$ coherence time of the singlet-triplet states in this system as a function of bias and magnetic field, obtaining a maximum $T_2^*$ of 60 ns, more than an order of magnitude higher than an electron spin in a single quantum dot. Our results uncover two main dephasing mechanisms: electrical noise away from the sweet spot, and a magnetic field dependent interaction with nuclear spins due to a difference in g-factors.
