Sb₂Te₃ is an end point of quasibinary GeTe–Sb₂Te₃ phase‐change alloys and also a prototypical topological insulator (TI). TIs are materials that behave like insulators in their interior but whose surfaces are characterized by metallic states with linear dispersion, the so‐called Dirac cones. Such surface states are symmetry protected, robust, and are maintained even in the presence of surface defects. It has been tacitly implied that any surfaces of a TI possess this property. Herein, using ab initio simulations, it is demonstrated that cleaving Sb₂Te₃ along certain side surfaces may lead to the disappearance of Dirac surface states. In particular, it is shown that the (110) surface of the typical TI Sb₂Te₃ is slightly gapped, whereas the ( $1\overline{1}0$) surface is metallic. The significance and potential benefits of the obtained results for practical applications in planar devices and memory cells are discussed.

中文翻译：

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结晶Sb2Te3：狄拉克锥的侧面和消失

Sb ₂ Te ₃是准二元GeTe–Sb ₂ Te ₃相变合金的终点，也是典型的拓扑绝缘体（TI）。TI是在内部具有类似绝缘体性能的材料，但其表面具有线性弥散的金属状态，即所谓的狄拉克锥。这样的表面状态受到对称保护，坚固并且即使在存在表面缺陷的情况下也得以保持。默示暗示TI的任何表面都具有此属性。在此，使用从头算模拟，说明了Sb ₂ Te _3的裂解。沿着某些侧面可能会导致狄拉克表面状态的消失。特别是，它显示了典型TI Sb ₂ Te ₃的（110）表面略有缝隙，而（$\mathrm{1个}\overline{\mathrm{1个}}0$）表面是金属的。讨论了获得的结果在平面器件和存储单元中的实际应用的意义和潜在的好处。