Quantum limit properties of Weyl semimetals

 · Invited

Abstract

Electrons confined to their 0th Landau level by extreme magnetic fields—a regime known as the quantum limit—experience strong electron-electron interactions, making them unstable to the formation of new states of matter. The discovery of monopnictide Weyl semimetals has renewed interest in the high-field properties of 3D electrons, with the added twist of linear electronic dispersions. We use magnetic fields up to 95 Tesla to take the Weyl semimetals NbP and TaAs into their quantum limit. In electrical transport and torque magnetometry, we identify signatures of the 0th Landau levels that are unique to Weyl fermions. In NbP, we show that Weyl fermions can be accessed in high fields, even when the zero-field chemical potential lies far from the nodes. In TaAs, we find that the left and right Weyl nodes are mixed by magnetic field, which opens a gap and suppresses the anomalous "ABJ"-induced conductivity. At the very highest fields in TaAs, we observe a thermodynamic phase transition to an as-yet unidentified state, indicating that Weyl semimetals are unstable to the formation of new states of matter.

*LANL LDRD 20160616ECR ‘New States of Matter in Weyl Semimetals’, DOE BES ‘Science of 100 Tesla’, and NSF grant No. 1752784: "Career: the Extreme Quantum Limit of Weyl Semimetals"

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Presenters

  • Brad Ramshaw

    • Cornell University
    • Laboratory of Atomic and Solid State Physics, Cornell University
    • Physics, Cornell University
    • Laboratory of atomic and solid state physics, Cornell university

Authors

  • Brad Ramshaw

    • Cornell University
    • Laboratory of Atomic and Solid State Physics, Cornell University
    • Physics, Cornell University
    • Laboratory of atomic and solid state physics, Cornell university

  • Kimberly Modic

    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute for chemical physics of solids

  • Ross McDonald

    • Los Alamos National Laboratory
    • Los Alamos National Labs
    • National High Magnetic Field Laboratory, LANL
    • Pulsed Field Faclity, National High Magnetic Field Laboratory
    • National High Magnetic Field Laboratory

  • Arkady Shekhter

    • National High Magnetic Field Laboratory
    • National High Field magnet Lab
    • Los Alamos National Labs

  • Eric Bauer

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA
    • Los Alamos National Laboratory
    • MPA-CMMS, Los Alamos National Laboratory, Los Alamos, USA
    • MPA-CMMS, Los Alamos National Laboratory
    • Los Alamos National Laboratory, Los Alamos, New Mexico, USA
    • Los Alamos National Labs

  • Filip Ronning

    • Los Alamos National Laboratory, Los Alamos, NM 87545, USA
    • Los Alamos National Laboratory
    • MPA-CMMS, Los Alamos National Laboratory, Los Alamos, USA
    • MPA-CMMS, Los Alamos National Laboratory
    • Los Alamos National Laboratory, Los Alamos, New Mexico, USA
    • Los Alamos National Labs

  • Tobias Meng

    • Institute for Theoretical Physics, Technical University Dresden
    • TU Dresden

  • Yi Zhang

    • Cornell University
    • Department of Physics, Cornell University

  • Eun-Ah Kim

    • Cornell University
    • Department of Physics, Cornell University

  • Mun Chan

    • Los Alamos National Laboratory
    • Los Alamos National Labs

  • Fedor Balakirev

    • Los Alamos National Laboratory
    • Los Alamos National Labs
    • Los Alamos, National High Magnetic Field Laboratory
    • National High Magnetic Field Lab, Los Alamos National Laboratory, Los Alamos, USA
    • National High Magnetic Field Laboratory

  • Albert Migliori

    • Los Alamos National Labs

  • Philip Moll

    • Ecole polytechnique federale de Lausanne
    • Swiss Federal Institute of Technology in Lausanne
    • École Polytechnique Fédérale de Lausanne (EPFL), Institute of Materials, Lausanne, Switzerland
    • Institute of Materials, Ecole Polytechnique Federale de Lausanne
    • Ecole Polytechnique Federale de Lausanne

  • Maja Bachmann

    • Max Planck Institute for Chemical Physics of Solids
    • Max Planck Institute for Chemical Physics of Solids, Dresden, Germany

  • Nirmal Ghimire

    • Argonne National Laboratory
    • Department of Physics and Astronomy, George Mason University