Spectroscopic evidence for a type II Weyl semimetallic state in MoTe 2

Lunan Huang, Timothy M. McCormick, Masayuki Ochi, Zhiying Zhao, Michi To Suzuki, Ryotaro Arita, Yun Wu, Daixiang Mou, Huibo Cao, Jiaqiang Yan, Nandini Trivedi, Adam Kaminski

Research output: Contribution to journalArticlepeer-review

334 Citations (Scopus)

Abstract

In a type I Dirac or Weyl semimetal, the low-energy states are squeezed to a single point in momentum space when the chemical potential μ is tuned precisely to the Dirac/Weyl point. Recently, a type II Weyl semimetal was predicted to exist, where the Weyl states connect hole and electron bands, separated by an indirect gap. This leads to unusual energy states, where hole and electron pockets touch at the Weyl point. Here we present the discovery of a type II topological Weyl semimetal state in pure MoTe 2, where two sets of Weyl points (,) exist at the touching points of electron and hole pockets and are located at different binding energies above E F. Using angle-resolved photoemission spectroscopy, modelling, density functional theory and calculations of Berry curvature, we identify the Weyl points and demonstrate that they are connected by different sets of Fermi arcs for each of the two surface terminations. We also find new surface track states' that form closed loops and are unique to type II Weyl semimetals. This material provides an exciting, new platform to study the properties of Weyl fermions.

Original languageEnglish
Pages (from-to)1155-1160
Number of pages6
JournalNature Materials
Volume15
Issue number11
DOIs
Publication statusPublished - 2016 Nov 1
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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