Prediction of topological insulating behavior in crystalline Ge-Sb-Te
Prediction of topological insulating behavior in crystalline Ge-Sb-Te
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DOI：
10.1103/physrevb.82.201312
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发表时间：
2010-11
影响因子：
3.7
通讯作者：
Jeongwoo Kim;Jinwoong Kim;S. Jhi
中科院分区：
文献类型：
--
作者：
Jeongwoo Kim;Jinwoong Kim;S. Jhi
我们通过第一性原理计算发现，结晶 Ge-Sb-Te (GST) 相变材料表现出拓扑绝缘特性。我们的计算表明，材料会变成拓扑绝缘体或根据层堆叠顺序形成导电的表面状界面态。结果表明，导电界面态源自 GST 中的拓扑绝缘 ${\text{Sb}}_{2}{\text{Te}}_{3}$ 层，对于化合物的电子性质至关重要。人们发现这些界面态对原子无序具有相当的弹性，但对单轴应变敏感。我们提出了破坏 GST 中拓扑绝缘顺序的机制，并研究了 Ge 迁移的作用，据信 Ge 迁移是 GST 非晶化的原因。
We report a discovery, through first-principles calculations, that crystalline Ge-Sb-Te (GST) phase-change materials exhibit the topological insulating property. Our calculations show that the materials become topological insulator or develop conducting surfacelike interface states depending on the layer stacking sequence. It is shown that the conducting interface states originate from topological insulating ${\text{Sb}}_{2}{\text{Te}}_{3}$ layers in GSTs and can be crucial to the electronic property of the compounds. These interface states are found to be quite resilient to atomic disorders but sensitive to the uniaxial strains. We presented the mechanisms that destroy the topological insulating order in GSTs and investigated the role of Ge migration that is believed to be responsible for the amorphorization of GSTs.