Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong, People's Republic of China.
Nanotechnology. 2011 Sep 30;22(39):395201. doi: 10.1088/0957-4484/22/39/395201. Epub 2011 Sep 2.
We study adiabatic quantum pumping in bilayer graphene where two-barrier potentials are weakly modulated as pumping parameters. Comparing the results with those for a normal quantum pump of non-chiral quasiparticles, we find that the chirality of quasiparticles in bilayer graphene heavily affects the pumped current through chiral tunnelling. When an exchange splitting induced by the proximity of a ferromagnetic insulator is introduced, the pumped current becomes spin-polarized. It is interesting that an almost 100% polarized charge current and a pure spin current with vanishing charge current can all be achieved under suitable conditions. The experimental feasibility and the interlayer asymmetric effect in bilayer graphene caused by the gate and the ferromagnet structures are also discussed. The results are useful for spintronics applications based on graphene.
我们研究了双层石墨烯中的绝热量子泵浦，其中两个势垒作为泵送参数被弱调制。将结果与非手性准粒子的普通量子泵浦进行比较，我们发现双层石墨烯中的准粒子的手性严重影响了通过手性隧道的泵送电流。当由铁磁绝缘体的接近引起的交换分裂被引入时，泵送电流变得自旋极化。有趣的是，在适当的条件下，可以实现几乎 100%极化的电荷电流和具有零电荷电流的纯自旋电流。还讨论了双层石墨烯中由于栅极和铁磁结构引起的层间非对称效应以及实验的可行性。这些结果对于基于石墨烯的自旋电子学应用是有用的。
