Spin-dependent current through a quantum dot from spin-polarized nonequilibrium quantum Hall edge channels
Spin-dependent current through a quantum dot from spin-polarized nonequilibrium quantum Hall edge channels
复制标题
自旋极化非平衡量子霍尔边缘通道通过量子点的自旋相关电流
DOI：
10.1103/physrevb.91.155302
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发表时间：
2015
影响因子：
3.7
通讯作者：
S. Tarucha
中科院分区：
文献类型：
--
作者：
H. Kiyama;T. Nakajima;S. Teraoka;A. Oiwa;S. Tarucha
我们报告了自旋上和自旋下的单电子选择性注入到量子点（QD）从自旋极化的非平衡量子霍尔边缘通道（EC）产生的自旋分辨EC的选择性传输使用的表面门放置在距离QD的距离。我们通过改变施加在不同源极欧姆接触上的偏置电压来改变非平衡电子晶体的自旋极化。上自旋电子注入效率达到0.5，比量子点与内皮细胞之间自旋相关的隧道耦合效率高出约0.2。另一方面，自旋下降电子注入的效率达到0.4。此外，我们纠正低估的自旋过滤的效率平衡EC的数值减去量子点中的激发态的贡献。所获得的自旋过滤效率高于从原始实验数据评估，并增加与预期的EC之间的空间分离的增加与磁场。
We report selective injection of both spin-up and spin-down single electrons into a quantum dot (QD) from spin-polarized nonequilibrium quantum Hall edge channels (ECs) generated by selective transmission of spin-resolved ECs using a surface gate placed at a distance from the QD. We change the spin polarization of nonequilibrium ECs by changing the bias voltages applied to different source Ohmic contacts. The efficiency of spin-up electron injection reaches 0.5, which is approximately 0.2 higher than that induced by spin-dependent tunnel coupling between QD and ECs. On the other hand, the efficiency of spin-down electron injection reaches 0.4. In addition, we rectify the underestimation of the efficiency of spin filtering for equilibrium ECs by numerically subtracting the contribution of the excited states in the QD. The obtained spin-filtering efficiency is higher than that evaluated from the raw experimental data and increases with magnetic field as expected with the increase in the spatial separation between ECs.