Thermodynamic Signatures of Weyl Fermions in NbP

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • K. A. Modic - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Tobias Meng - , Chair of Theoretical Solid State Physics (Author)
  • Filip Ronning - , Los Alamos National Laboratory (Author)
  • Eric D. Bauer - , Los Alamos National Laboratory (Author)
  • Philip J.W. Moll - , Max Planck Institute for Chemical Physics of Solids (Author)
  • B. J. Ramshaw - , Cornell University (Author)

Abstract

We present a high magnetic field study of NbP—a member of the monopnictide Weyl semimetal (WSM) family. While the monoarsenides (NbAs and TaAs) have topologically distinct left and right-handed Weyl fermi surfaces, NbP is argued to be “topologically trivial” due to the fact that all pairs of Weyl nodes are encompassed by a single Fermi surface. We use torque magnetometry to measure the magnetic response of NbP up to 60 tesla and uncover a Berry paramagnetic response, characteristic of the topological Weyl nodes, across the entire field range. At the quantum limit B* (≈32 T), τ/B experiences a change in slope when the chemical potential enters the last Landau level. Our calculations confirm that this magnetic response arises from band topology of the Weyl pocket, even though the Fermi surface encompasses both Weyl nodes at zero magnetic field. We also find that the magnetic field pulls the chemical potential to the chiral n = 0 Landau level in the quantum limit, providing a disorder-free way of accessing chiral Weyl fermions in systems that are “not quite” WSMs in zero magnetic field.

Details

Original languageEnglish
Article number2095
JournalScientific reports
Volume9
Issue number1
Publication statusPublished - 1 Dec 2019
Peer-reviewedYes

External IDs

PubMed 30765755

Keywords

ASJC Scopus subject areas