Long-wavelength incommensurate spin structure in the non-centrosymmetric Weyl semimetal NdAlSi

ORAL

Abstract

Weyl fermions can be stabilized in crystals that break inversion or time-reversal symmetry. NdAlSi has a non-centrosymmetric crystal structure and is also magnetic, so it breaks both of these symmetries. NdAlSi is thus an excellent template to study the connection between magnetism, electronic transport, and the Weyl fermions. To do so, we characterized the magnetism of NdAlSi using neutron diffraction and found a ferrimagnetic state at low temperature, which is followed by a long-wavelength incommensurate order at finite temperature. A combination of quantum oscillations measurements and DFT calculations were then performed to determine the Fermi surface of NdAlSi. We found that the periodicity of the magnetic order in NdAlSi matches the momentum space vector that connects two of its Fermi pockets. The Fermi pockets involved in this interaction contain Weyl fermions, which raises the interesting possibility for magnetic order driven by relativistic electrons in NdAlSi.

*This work was supported as part of the Institute for Quantum Matter, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No.DE-SC0019331.

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Presenters

  • Jonathan Gaudet

    • Department of Physics and Astronomy and Institute for Quantum Matter, The Johns Hopkins University
    • Johns Hopkins University
    • Department of Physics and Astronomy and Institute for Quantum Matter, Johns Hopkins University, Baltimore, Maryland 21218, USA

Authors

  • Jonathan Gaudet

    • Department of Physics and Astronomy and Institute for Quantum Matter, The Johns Hopkins University
    • Johns Hopkins University
    • Department of Physics and Astronomy and Institute for Quantum Matter, Johns Hopkins University, Baltimore, Maryland 21218, USA

  • Hung-Yu Yang

    • Department of Physics, Boston College
    • Boston College
    • Department of Physics, Boston College, Chestnut Hill, MA 02467, USA

  • Santu Baidya

    • Rutgers University
    • Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University

  • Baozhu Lu

    • Department of Physics and Temple Materials Institute, Temple University
    • Temple University

  • Guangyong Xu

    • NIST
    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standard and Technology
    • Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standards and Technology
    • Center of Neutron Research, National Institute of Standards and Technology, NIST
    • NIST Center for Neutron Research, NIST

  • Yang Zhao

    • NIST Center for Neutron Research,, National Institute of Standards and Technology
    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standard and Technology
    • Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standards and Technology

  • Jose A. Rodriguez-Rivera

    • National Institute of Standard and Technology
    • Center for Neutron Research, NIST
    • NIST
    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • NIST Center for Neutron Research

  • Christina Hoffmann

    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory,

  • David E Graf

    • National High Magnetic Field Laboratory
    • Florida State University
    • National High Magnetic Field Lab, Florida State University
    • National High Magnetic Field Laboratory, Tallahassee and Florida State University
    • National High Magnetic Field Laboratory, Florida State University
    • National High Magnetic Field Laboratory (FSU)
    • Department of Physics, Florida State University
    • National High Magnetic Field Laboratory and Department of Physics, Florida State University
    • National High Magnetic Field Lab
    • National High Magnetic Field Laboratory, Tallahassee, FL
    • CMS, National High Magnetic Laboratory

  • Darius Torchinsky

    • Department of Physics and Temple Materials Institute, Temple University
    • Temple University

  • David Vanderbilt

    • Rutgers University, New Brunswick
    • Rutgers University
    • Physics, Rutger Univeristy
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, USA

  • Fazel Tafti

    • Boston College
    • Department of Physics, Boston College
    • Department of Physics, Boston College, Chestnut Hill, MA 02467, USA

  • Collin Leslie Broholm

    • Johns Hopkins University
    • Department of Physics and Astronomy and Institute for Quantum Matter, The Johns Hopkins University
    • Department of Physics and Astronomy and Institute for Quantum Matter, Johns Hopkins University, Baltimore, Maryland 21218, USA
    • Institute for Quantum Matter and Department of Physics and Astronomy, Johns Hopkins University
    • Physics, The Johns Hopkins University