The electron scattering from periodic line defects on the surface of topological insulators with hexagonal warping effect is investigated theoretically by means of a transfer matrix method. The influence of surface line defects, acting as structural ripples on propagation of electrons are studied in two perpendicular directions due to the asymmetry of warped energy contour under momentum exchange. The transmission profiles and the details of resonant peaks which vary with the number of defects and the strength of their potentials are strongly dependent on the direction in which the line defects extend. At low energies, the quantum interference between the incident and reflected propagating electrons has the dominant contribution in transmission resonances, while at high energies the multiple scattering processes on the constant-energy contour also appear because of the strong warping effect. By increasing the spatial separation between the line defects, the minimum value of electrical conductance remains significantly high at low incident energies, while the minimum value may approach zero at high energies as the number of defects is increased. Our findings suggest that the potential ripples on the surface of topological insulators can be utilized to control the local electronic properties of these materials.

中文翻译：

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拓扑绝缘体表面线缺陷超晶格中的电子散射

采用转移矩阵法从理论上研究了具有六边形翘曲效应的拓扑绝缘体表面周期线缺陷的电子散射。由于动量交换下翘曲能量轮廓的不对称性，在两个垂直方向上研究了作为结构波纹对电子传播的表面线缺陷的影响。随缺陷数量及其电位强度而变化的传输曲线和谐振峰的细节强烈依赖于线缺陷延伸的方向。在低能量下，入射电子和反射传播电子之间的量子干涉在传输共振中起主要作用，而在高能量下，由于强烈的翘曲效应，恒定能量等高线上也会出现多次散射过程。通过增加线缺陷之间的空间间隔，在低入射能量下电导的最小值仍然非常高，而随着缺陷数量的增加，在高能量下最小值可能接近零。我们的研究结果表明，拓扑绝缘体表面的潜在波纹可用于控制这些材料的局部电子特性。而随着缺陷数量的增加，最小值可能在高能量下接近零。我们的研究结果表明，拓扑绝缘体表面的潜在波纹可用于控制这些材料的局部电子特性。而随着缺陷数量的增加，最小值可能在高能量下接近零。我们的研究结果表明，拓扑绝缘体表面的潜在波纹可用于控制这些材料的局部电子特性。