与铁磁电极耦合的双量子点中近藤效应的研究

研究了与铁磁电极耦合的串连双量子点中的平衡和非平衡近藤效应，同时考虑了两侧电极中自旋极化的态密度为平行和反平行的情况。结果表明，每个量子点的平衡态密度在平行情况下只有一个尖峰，当有外加偏压的时候，这个尖峰将分裂为两个；在反平行情况下，每个量子点的平衡态密度有两个尖峰，分别对应与电子的两种不同自旋取向，自旋向下和向上的态密度双峰之间的距离将在外加偏压的影响下分别增大和减少。在反平行情况下，每一种自旋成份的微分电导只有一个尖峰，并且分别在费米面之上和之下；而在平行情况下，每种自旋成份的微分电导都有两个尖峰，其中自旋朝下的微分电导尖峰较高。

Kondo effect in double quantum dots coupled to ferromagnetic leads

We study the equilibrium and non--equilibrium Kondo effect in series--coupled double quantum dots connected to ferromagnetic leads both in parallel and antiparallel configurations. We show that for the parallel confguration,the equilibrium density of states has one peak on each dot and splits into two when an external voltage is applied. Whereas for the antiparallel case on each dot,the equilibrium DOS has two peaks for both spin orientation. The applied voltage increases the spacing of the spin--down double peaks but shortens that of the spin--up ones. The differential conductance of each spin in the antiparallel configuration has one peak on each side of the chemical potential,while two peaks emerge in the parallel situation,with the spin--down ones being much higher.