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arXiv 0812.2359cond-mat.mes-hall
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周期介观网络中量子干涉引起的自旋滤波

Spin filtering due to quantum interference in periodic mesoscopic networks

Amnon Aharony, Ora Entin-Wohlman, Yasuhiro Tokura, Shingo Katsumoto

摘要:

我们提出了几个新的结果,扩展了我们最近提出的自旋过滤器的紧束缚模型的基础上的周期性链的钻石样环[物理。修订B { \bf 78},125328(2008)]。在该滤波器中,Rashba自旋-轨道相互作用(其可以通过垂直栅极电压来调谐)和Aharonov-Bohm通量(由于垂直磁场)组合以仅选择一个传播弹道模式。对于这种模式,电子自旋沿着可以由电场和磁场以及电子能量控制的方向完全极化。所有其他模式都是短暂的。将正方形菱形推广为具有任意开口角度的菱形,我们发现增加这些角度拓宽了有效滤波的参数范围。在每个菱形的两侧上的不同的栅极电压被发现对带中心的一侧上的能量的电子离域。我们还比较了我们的紧束缚模型与使用一维导线的连续量子网络的模型,并发现只有当一个选择特定的网站能量在网络的节点重合。

英文摘要:

We present several new results, extending our recent proposal of a spin filter based on a tight-binding model for a periodic chain of diamond-like loops [Phys. Rev. B {\bf 78}, 125328 (2008)]. In this filter, the Rashba spin-orbit interaction (which can be tuned by a perpendicular gate voltage) and the Aharonov-Bohm flux (due to a perpendicular magnetic field) combine to select only one propagating ballistic mode. For this mode, the electronic spins are fully polarized along a direction that can be controlled by the electric and magnetic fields and by the electron energy. All the other modes are evanescent. Generalizing the square diamonds into rhombi with arbitrary opening angles, we find that increasing these angles widens the parameter range for efficient filtering. A different gate voltage on the two sides of each rhombus is found to delocalize the electrons for energies on one side of the band center. We also compare our tight-binding model with models which use continuous quantum networks of one-dimensional wires, and find coincidence only when one chooses particular site energies at the nodes of the network.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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