Pauli spin blockade in weakly coupled double quantum dots
Pauli spin blockade in weakly coupled double quantum dots
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DOI：
10.1103/physrevb.73.205333
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发表时间：
2006-05-01
影响因子：
3.7
通讯作者：
Rasander, M.
中科院分区：
文献类型：
--
作者：
Fransson, J.;Rasander, M.
在由两个串联耦合的单级量子点构成并耦合到外部引线的两级系统中，我们发现电流在一个偏压方向上受到抑制，这是由相互作用区域中完全占据的二电子三重态引起的。电流抑制的效率由点间隧道速率和能级偏移之间的比率决定。在相反的偏置方向上，二电子三重态的占据被提升，这允许更大的电流流过系统，其中电导由一电子态和二电子单重态之间的跃迁提供。还表明，有限的铁磁点间交换相互作用提供了电流抑制的扩展范围，而反铁磁交换导致封锁范围的减小。
In a two-level system, constituted by two serially coupled single level quantum dots, coupled to external leads we find that the current is suppressed in one direction of biasing caused by a fully occupied two-electron triplet state in the interacting region. The efficiency of the current suppression is governed by the ratio between the interdot tunnelling rate and the level offset. In the opposite bias direction, the occupation of the two-electron triplet is lifted which allows a larger current to flow through the system, where the conductance is provided by transitions between one-electron states and two-electron singlet states. It is also shown that a finite ferromagnetic interdot exchange interaction provides an extended range of the current suppression, while an antiferromagnetic exchange leads to a decreased range of the blockade regime.