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利用粒子数分辨量子主方程,研究了单量子点与两个铁磁电极耦合系统内有效核磁场对电子全计数统计特性的影响。数值结果表明有效核磁场的大小和方向对平均电流基本上没有影响;但是,仅有单占据与空占据量子点本征态之间的转变参与量子输运时,特别是,当两个铁磁电极自旋极化率较大,并且量子点电极耦合强度大于有效核磁场大小时,有效核磁场的大小和方向对散粒噪声和偏斜度有显著的影响。因此,可以基于量子点的电流高阶累积矩来定性获取其有效核磁场大小和方向的信息。
The effect of the effective nuclear magnetic field in the coupling system between the single quantum dot and the two ferromagnetic electrodes on the statistics of the electronic total count was studied by using the particle number resolution quantum principal equation. The numerical results show that the size and direction of the effective nuclear magnetic field have almost no effect on the average current; however, only the transition between the single-occupancy and empty-occupied quantum dot eigenstates participates in quantum transport, especially when two ferromagnets When the spin polarization of the electrode is large and the coupling strength of the quantum dot electrode is larger than the effective nuclear magnetic field, the size and direction of the effective nuclear magnetic field have a significant effect on shot noise and skewness. Therefore, it is possible to qualitatively obtain the information of the effective nuclear magnetic field size and direction based on the high-order cumulated moment of the current of the quantum dot.