Weyl Nodes Close to the Fermi Energy in NbAs

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Marcel Naumann - , Max Planck Institute for Chemical Physics of Solids, Technical University of Munich (Author)
  • Frank Arnold - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Zuzana Medvecka - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Shu Chun Wu - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Vicky Süss - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Marcus Schmidt - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Binghai Yan - , Weizmann Institute of Science (Author)
  • Nico Huber - , Technical University of Munich (Author)
  • Lukas Worch - , Technical University of Munich (Author)
  • Marc A. Wilde - , Technical University of Munich (Author)
  • Claudia Felser - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Yan Sun - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Elena Hassinger - , Max Planck Institute for Chemical Physics of Solids, Technical University of Munich (Author)

Abstract

The noncentrosymmetric transition-metal monopnictides NbP, TaP, NbAs, and TaAs are a family of Weyl semimetals in which pairs of protected linear crossings of spin-resolved bands occur. These so-called Weyl nodes are characterized by integer topological charges of opposite sign associated with singular points of Berry curvature in momentum space. In such a system, anomalous magnetoelectric responses are predicted, which should only occur if the crossing points are close to the Fermi level and enclosed by Fermi surface pockets penetrated by an integer flux of Berry curvature, dubbed Weyl pockets. TaAs is shown to possess Weyl pockets, whereas TaP and NbP have trivial pockets enclosing zero net flux of Berry curvature. Herein, via measurements of the magnetic torque, resistivity, and magnetization, a comprehensive quantum-oscillation study of NbAs is presented, the last member of this family where the precise shape and nature of the Fermi surface pockets is still unknown. Seven distinct frequency branches, three of which have not been observed before, are detected. A comparison with density functional theory calculations suggests that the two largest pockets are topologically trivial, whereas the low frequencies might stem from tiny Weyl pockets. The enclosed Weyl nodes are within a few meV of the Fermi energy.

Details

Original languageEnglish
Article number2100165
JournalPhysica Status Solidi (B) Basic Research
Volume259
Issue number5
Publication statusPublished - May 2022
Peer-reviewedYes
Externally publishedYes

Keywords

Keywords

  • Fermi surfaces, quantum oscillations, Weyl semimetals