Dirac electron behavior and NMR evidence for topological band inversion in ZrTe5

2019/10/16 by Yefan Tian, Nader Ghassemi, Joseph H. Ross Jr · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci

paper · pdf · doi:10.1103/physrevb.100.165149

published as Phys. Rev. B 100, 165149 (2019) · 5 pages, 4 figures

arxiv created 2019/10/16 · arxiv updated 2019/11/01

Abstract

We report ¹²⁵Te NMR measurements of the topological quantum material ZrTe₅. Spin-lattice relaxation results, well-explained by a theoretical model of Dirac electron systems, reveal that the topological characteristic of ZrTe₅ is T-dependent, changing from weak topological insulator to strong topological insulator as temperature increases. Electronic structure calculations confirm this ordering, the reverse of what has been proposed. NMR results demonstrate a gapless Dirac semimetal state occurring at a Lifshitz transition temperature, T_c=85 K in our crystals. We demonstrate that the changes in NMR shift at T_c also provide direct evidence of band inversion when the topological phase transition occurs.

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• DFT based insights into elastic, thermophysical, electronic and optical properties of topological insulators XTe5 (X = Zr, Hf)