Transition between strong and weak topological insulator in ZrTe₅ and HfTe₅

2016/11/30 by Zongjian Fan, Qi-Feng Liang, Y. B. Chen +2 · 2 citations
Physics and Astronomy · #cond-mat.mtrl-sci

paper · pdf · doi:10.1038/srep45667

published as Scientific Reports 7 45667 (2017) · 6 pages, 4 figures

arxiv created 2017/03/04 · arxiv updated 2017/04/10

Abstract

ZrTe₅ and HfTe₅ have attracted increasingly attention recently since the theoretical prediction of being topological insulators (TIs). However, subsequent works show many contradictions about their topological nature.Three possible phases, i.e. strong TI, weak TI, and Dirac semi-metal, have been observed in different experiments until now. Essentially whether ZrTe₅ or HfTe₅ has a band gap or not is still a question. Here, we present detailed first-principles calculations on the electronic and topological properties of ZrTe₅ and HfTe₅ on variant volumes and clearly demonstrate the topological phase transition from a strong TI, going through an intermediate Dirac semi-metal phase, then to a weak TI when the crystal expands.Our work might give a unified explain about the divergent experimental results and propose the crucial clue to further experiments to elucidate the topological nature of these materials.

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