Tunable energy bands and spin filtering in two-dimensional superlattices with spin-orbit interaction
Tunable energy bands and spin filtering in two-dimensional superlattices with spin-orbit interaction
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DOI：
10.1063/1.3684715
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发表时间：
2012-03
影响因子：
3.2
通讯作者：
R. Zhang;Jia Li;D. Qi;Qing Hu;R. Peng;R. Huang;Mu Wang
中科院分区：
文献类型：
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作者：
R. Zhang;Jia Li;D. Qi;Qing Hu;R. Peng;R. Huang;Mu Wang
在二维超晶格中，周期性地施加量子垒、矩阵和威尔斯阱的方棒，研究了Rashba自旋轨道耦合（SOC）和磁场对超晶格电子能带和自旋滤波的影响.结果表明，电子能谱形成能带结构，能级被Rashba SOC分裂，相应地，电导随电子能量的变化呈现“带隙”结构.通过控制SOC的强度，对于自旋向上的电子，“带”中的电导增强，而对于自旋向下的电子，电导减小。有趣的是，通过引入磁调制，自旋向上和自旋向下的电子的电导曲线在不同的方向上平移。结果，观察到高自旋极化，并且在该2DSL中实现完全自旋极化电导。此外，还得到了电子波函数，清晰地显示了自旋滤波的图象。
We theoretically investigate the electronic energy bands and spin filtering tuned by Rashba spin-orbit coupling (SOC) and magnetic field in two-dimensional superlattices (2DSLs), where the square rods of quantum barriers, matrix, and wells are imposed periodically. It is shown that electronic energy spectra form a band structure and the energy levels are split up by the Rashba SOC. Correspondingly, the electrical conductance presents a “band-gap” structure against the electron energy. With manipulating the strength of SOC, the conductance in the “band” is enhanced for the spin-up electrons, while it is reduced for the spin-down electrons. Interestingly, by introducing a magnetic modulation, conductance curves for spin-up and spin-down electrons are translated in the different directions. As a result, high spin polarization is observed, and fully spin-polarized conductance is achieved in this 2DSL. Furthermore, the electronic wavefunctions have been obtained, which presents a clear picture of spin filterin...