arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2209.02102cond-mat.mes-hall
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石墨烯系统中的全电谷滤波(II):谷阀中电子输运的数值研究

All-electrical valley filtering in graphene systems (II): Numerical study of electron transport in valley valves

Jia-Huei Jiang, Ning-Yuan Lue, Feng-Wu Chen, Yu-Shu G. Wu

摘要:

本文对谷电子学中的基本逻辑门--由两个或更多个谷滤波器组成的谷阀--的电子输运进行了数值研究。各种典型的影响的运输进行了研究,如那些由于界面散射,长和短距离杂质散射,边缘粗糙度,应变,过滤器间的间距,或增加数量的谷过滤器。为了说明,我们考虑由单层或双层石墨烯中的石墨烯量子线谷过滤器构建的特定阀的类别,其中过滤器受到面内横向电场的单独控制。利用石墨烯的最近邻紧束缚模型建立了相应的输运问题,并采用递推格林函数法求解相应的透射系数。在两个过滤器阀的情况下,结果明确地证明了存在一个显着的开关对比度的电子传输之间的两种配置的阀门,即,一个具有相同的和另一个具有相反的谷极性的两个组成过滤器。当增加阀中过滤器的数量时,对比度被示出增强。Fano-Fabry-Perot型共振与界面散射和滤波器间距的签名进行了说明。电子背散射由于杂质被发现是sizably抑制,与阀的性能表现出相当大的鲁棒性对边缘粗糙度散射。另一方面,单轴应变的存在下修改电子传输和结果在一个有趣的准周期调制的传输,因为我们改变应变强度。

英文摘要:

This work performs a numerical study of electron transport through the fundamental logic gate in valleytronics - a valley valve consisting of two or increasing number of valley filters. Various typical effects on the transport are investigated, such as those due to interface scattering, long- and short- range impurity scattering, edge roughness, strain, inter-filter spacing, or increasing number of valley filters. For illustration, we consider the class of specific valves built from graphene quantum wire valley filters in single layer or bilayer graphene, with the filters subject to separate control of in-plane, transverse electric fields. The nearest-neighbor tight-binding model of graphene is used to formulate the corresponding transport problem, and the algorithm of recursive Green's function method is applied to solve for the corresponding transmission coefficient. In the case of two-filter valves, the result explicitly demonstrates the existence of a pronounced on-off contrast in electron transmission between the two configurations of valves, namely, one with identical and the other with opposite valley polarities in the two constituent filters. The contrast is shown to be enhanced when increasing the number of filters in valves. Signatures of Fano-Fabry-Perot type resonances in association with interface scattering and inter-filter spacing are illustrated. Electron backscattering due to impurities is found to be sizably suppressed, with the valve performance showing considerable robustness against edge roughness scattering. On the other hand, the presence of a uniaxial strain modifies the electron transmission and results in an interesting quasi-periodic modulation of transmission as we vary the strain strength.

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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