Polytypism, Anisotropic Transport, and Weyl Nodes in the van der Waals Metal TaFeTe4

Ren A. Wiscons, Yeongsu Cho, Sae Young Han, Avalon H. Dismukes, Elena Meirzadeh, Colin Nuckolls, Timothy C. Berkelbach, Xavier Roy

Research output: Contribution to journalArticlepeer-review


Layered van der Waals (vdW) materials belonging to the MM′Te4 structure class have recently received intense attention due to their ability to host exotic electronic transport phenomena, such as in-plane transport anisotropy, Weyl nodes, and superconductivity. Here we report two new vdW materials with strongly anisotropic in-plane structures featuring stripes of metallic TaTe2 and semiconducting FeTe2, α-TaFeTe4 and β-TaFeTe4. We find that the structure of α-TaFeTe4 produces strongly anisotropic in-plane electronic transport (anisotropy ratio of up to 250%), outcompeting all other vdW metals, and demonstrate that it can be mechanically exfoliated to the two-dimensional (2D) limit. We also explore the possibility that broken inversion symmetry in β-TaFeTe4 produces Weyl points in the electronic band structure. Eight Weyl nodes slightly below the Fermi energy are computationally identified for β-TaFeTe4, indicating they may contribute to the transport behavior of this polytype. These findings identify the TaFeTe4 polytypes as an ideal platform for investigation of 2D transport anisotropy and chiral charge transport as a result of broken symmetry.

Original languageEnglish
Pages (from-to)109-113
Number of pages5
JournalJournal of the American Chemical Society
Issue number1
Early online date24 Dec 2020
StatePublished - 13 Jan 2021
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • Biochemistry
  • Catalysis
  • Colloid and Surface Chemistry


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