Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Nat Commun. 2017 May 23;8:15512. doi: 10.1038/ncomms15512.
The topological materials have attracted much attention for their unique electronic structure and peculiar physical properties. ZrTe has host a long-standing puzzle on its anomalous transport properties manifested by its unusual resistivity peak and the reversal of the charge carrier type. It is also predicted that single-layer ZrTe is a two-dimensional topological insulator and there is possibly a topological phase transition in bulk ZrTe. Here we report high-resolution laser-based angle-resolved photoemission measurements on the electronic structure and its detailed temperature evolution of ZrTe. Our results provide direct electronic evidence on the temperature-induced Lifshitz transition, which gives a natural understanding on underlying origin of the resistivity anomaly in ZrTe. In addition, we observe one-dimensional-like electronic features from the edges of the cracked ZrTe samples. Our observations indicate that ZrTe is a weak topological insulator and it exhibits a tendency to become a strong topological insulator when the layer distance is reduced.
拓扑材料因其独特的电子结构和奇异的物理性质而引起了广泛关注。ZrTe 因其异常的电阻率峰和载流子类型的反转而表现出反常的输运性质，这一直是一个长期存在的难题。此外，人们还预测单层 ZrTe 是一种二维拓扑绝缘体，在块状 ZrTe 中可能存在拓扑相变。在这里，我们报告了基于激光的高分辨率角分辨光发射测量，以研究 ZrTe 的电子结构及其详细的温度演化。我们的结果提供了关于温度诱导的 Lifshitz 转变的直接电子证据，这为 ZrTe 中电阻率异常的潜在起源提供了自然的理解。此外，我们还观察到来自 ZrTe 裂纹边缘的一维样电子特征。我们的观察表明，ZrTe 是一种弱拓扑绝缘体，当层间距离减小时，它表现出向强拓扑绝缘体转变的趋势。
