Charge and spin pumping through a double quantum dot
Charge and spin pumping through a double quantum dot
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DOI：
10.1103/physrevb.82.205308
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发表时间：
2010-11-08
影响因子：
3.7
通讯作者：
Splettstoesser, Janine
中科院分区：
文献类型：
--
作者：
Riwar, Roman-Pascal;Splettstoesser, Janine
我们计算了具有强库仑相互作用的串联双量子点与正常金属或铁磁接触耦合时的绝热电荷和自旋泵浦。在储层弱耦合的情况下，我们使用了实时图解方法。在弱点间隧道耦合的情况下，我们研究了电荷涨落引起的隧道重整化效应对抽运电荷和自旋的影响。我们表明，通过热激发态的隧穿可以在强的点间耦合区域中扮演重要的角色。特别是，对于铁磁接触，这两种效应都能产生纯自旋电流。此外，它们可能导致反转的自旋阀效应，甚至导致输运方向的反转，伴随着发散的隧道磁阻。
We calculate adiabatic charge and spin pumping through a serial double quantum dot with strong Coulomb interaction, coupled to normal metal or ferromagnetic contacts. We use a real-time diagrammatic approach in the regime of weak coupling to the reservoirs. In the case of weak interdot tunnel coupling we investigate the influence of tunnel-induced renormalization effects due to charge fluctuations on the pumped charge and spin. We show that tunneling through thermally excited states can play an important role in the strong interdot coupling regime. In particular, for ferromagnetic contacts, both effects enable the generation of pure spin currents. Furthermore they can lead to an inverted spin-valve effect or even to the inversion of the transport direction going along with a diverging tunneling magnetoresistance.