Energy dispersion and spin orientation of the protected states at an interface between topological insulators and nontopological materials depend on the charge redistribution, strain, and atomic displacement at the interface. Knowledge of these properties is essential for applications of topological compounds, but direct access to them in the interface geometry is difficult. We show that conductance of a gated double junction at the surface of a topological insulator exhibits oscillations and a quasilinear decay as a function of gate voltage in different regimes. These give the values for the quasiparticle velocities along and normal to the junction in the interface region, and determine the symmetry of the topological interface states. The results are insensitive to the boundary conditions at the junction.

中文翻译：

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门控连接的电导率作为拓扑界面状态的探针

拓扑绝缘体和非拓扑材料之间的界面处的受保护状态的能量扩散和自旋取向取决于界面处的电荷重新分布，应变和原子位移。这些特性的知识对于拓扑化合物的应用是必不可少的，但是很难在界面几何中直接访问它们。我们表明，在拓扑绝缘体的表面上门控双结的电导表现出振荡和准线性衰减，这是在不同状态下随栅极电压变化的函数。这些给出沿界面区域并垂直于界面区域的准粒子速度的值，并确定拓扑界面状态的对称性。结果对交界处的边界条件不敏感。