APS Logo

(TaSe4)<sub>2</sub>I: A Charge-Density-Wave Topological Semimetal

ORAL

Abstract

Topological physics and strong electron-electron correlations in quantum materials are typically studied independently. However, there have been rapid recent developments in quantum materials in which topological phase transitions emerge when the single-particle band structure is modified by strong interactions. In [Shi*, Wieder*, Meyerheim*, et al., Nat. Phys. (2021)], we demonstrate that the room-temperature phase of (TaSe4)2I is a Weyl semimetal with 24 pairs of Weyl nodes. Owing to its quasi-1D structure, (TaSe4)2I hosts an established CDW instability just below room temperature. Using X-ray diffraction, angle-resolved photoemission spectroscopy, and first-principles calculations, we find that the CDW in (TaSe4)2I couples the bulk Weyl points and opens a band gap. The correlation-driven topological phase transition in (TaSe4)2I provides a route towards observing condensed-matter realizations of axion electrodynamics in the gapped regime, topological chiral response effects in the semimetallic phase, and represents an avenue for exploring the interplay of correlations and topology in a solid-state material.

–

Presenters

  • Zhijun Wang

    Princeton University, Department of Physics, Chinese Academy of Sciences, Institute of Physics, Institute of Physics, Chinese Academy of Sciences, Chinese Academy of Sciences,Institute of Physics

Authors

  • Wujun Shi

    School of Physical Science and Technology, ShanghaiTech University

  • Benjamin J. Wieder

    Department of Physics, Massachusetts Institute of Technology, Massachusetts Institute of Technology

  • Holger L. Meyerheim

    Max Planck Institute of Microstructure Physics

  • Yan Sun

    Max Planck Institute for Chemical Physics of Solids, Max Planck, Dresden, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden

  • Yulin Chen

    School of Physical Science and Technology, ShanghaiTech University, Department of Physics, University of Oxford, University of Oxford, Unviersity of Oxford

  • Claudia Felser

    Max Planck Institute for Chemical Physics of Solids, Max Planck Institute for the Chemical Physics of Solids, Solid State Chemistry, Max Planck Institute for Chemical Physics of Solids, Max Planck Institute, Dresden, Germany, Max Planck, Dresden, Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Max Planck Institute for Chemical Physics of Solids,

  • Andrei Bernevig

    Princeton University, Department of Physics, Princeton University, Physics, Princeton University

  • Zhijun Wang

    Princeton University, Department of Physics, Chinese Academy of Sciences, Institute of Physics, Institute of Physics, Chinese Academy of Sciences, Chinese Academy of Sciences,Institute of Physics