Understand the spin and current behavior in the topological-insulator (TI) system is crucial for the design of electronic and spintronic devices. To study these behaviors, some three-terminal hetero-junction TI systems made from the zigzag silicene-like nanoribbons (ZSiNRs) are investigated. Different external fields are applied in the leads and conductor regions, which result in the expected topological edge states. By calculating the local current distribution, we find two important characteristics of topological edge current propagating in these systems. Firstly, the topological edge current prefers to flow into the nearest channel, rather than the other faraway channels. Secondly, the group-velocity mismatch as a scattering engineering has a significant effect on current propagation behavior. In other words, one can manipulate the topological edge current by velocity mismatch. Based on these characteristics, a type of three-terminal spin filter is proposed in this paper. Mor...

中文翻译：

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三端拓扑-绝缘子结中的电流传播行为和自旋滤波效应

了解拓扑绝缘体（TI）系统中的自旋和电流行为对于电子和自旋电子设备的设计至关重要。为了研究这些行为，研究了一些由之字形硅状纳米带（ZSiNRs）制成的三端异质结TI系统。在引线和导体区域中施加了不同的外部场，这导致了预期的拓扑边缘状态。通过计算局部电流分布，我们发现了在这些系统中传播的拓扑边缘电流的两个重要特征。首先，拓扑边缘电流更喜欢流入最近的通道，而不是其他遥远的通道。其次，作为散射工程的群速度失配对电流传播行为具有重要影响。换一种说法，可以通过速度失配来控制拓扑边缘电流。基于这些特性，本文提出了一种三端自旋滤波器。莫...