Temperature-induced Lifshitz transition in topological insulator candidate HfTe5

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2017,（13）
• 页码范围: 950-956
• 页数: 7页
• 语种: 英文

摘要

The ongoing discoveries and studies of novel topological quantum materials have become an emergent and important field of condensed matter physics.Recently,HfTe5 ignited renewed interest as a candidate of a novel topological material.The single-layer HfTe5 is predicted to be a two-dimensional large band gap topological insulator and can be stacked into a bulk that may host a temperature-driven topological phase transition.Historically,HfTe5 attracted considerable interest for its anomalous transport properties characterized by a peculiar resistivity peak accompanied by a sign reversal carrier type.The origin of the transport anomaly remains under a hot debate.Here we report the first high-resolution laser-based angle-resolved photoemission measurements on the temperature-dependent electronic structure in HfTe5.Our results indicated that a temperature-induced Lifshitz transition occurs in HfTe5,which provides a natural understanding on the origin of the transport anomaly in HfTe5.In addition,our observations suggest that HfTe5 is a weak topological insulator that is located at the phase boundary between weak and strong topological insulators at very low temperature.