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Polarization-resolved Raman spectroscopy of α-RuCl3 and evidence of room-temperature two-dimensional magnetic scattering

ORAL

Abstract

Polarization-resolved Raman spectroscopy was performed and analyzed from large, high-quality, monodomain single crystal of α-RuCl3, a proximate Kitaev quantum spin liquid1. Spectra were collected with laser polarizations parallel and perpendicular to the honeycomb plane. Pairs of nearly degenerate phonons were discovered and show either a fourfold or twofold polarization angle dependence in their Raman intensity, thereby providing evidence to definitively assign the bulk crystal point group as C2h. The low-frequency continuum that is often attributed to scattering from pairs of Majorana fermions was also examined and found to disappear when the laser excitation and scattered photon polarizations were perpendicular to the honeycomb plane. This disappearance, along with the behavior of the phonon spectrum in the same polarization configuration, strongly suggests that the scattering continuum is two-dimensional. We argue that this scattering continuum originates from the Kitaev magnetic interactions that survives up to room temperature, a scale larger than the bare Kitaev exchange energy of approximately 50 K.
1DOI: 10.1103/PhysRevB.100.134419

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Presenters

  • Angela Hight Walker

    National Institute of Standards and Technology, NIST, National Institute of Standards and Technology (NIST)

Authors

  • Angela Hight Walker

    National Institute of Standards and Technology, NIST, National Institute of Standards and Technology (NIST)

  • Thuc Mai

    NIST, National Institute of Standards and Technology

  • Amber McCreary

    NIST, National Institute of Standards and Technology

  • Paula Lampen-Kelley

    Oak Ridge National Laboratory, Material Science and Technology Division, Oak Ridge National Lab

  • Nicholas Butch

    NIST 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, Center for Neutron Research, National Institute of Standards and Technology, NIST Center for Neutron Research, NIST center for neutron research, NIST, NIST Center for Neutron Research, National Institute of Standards and Technology,, University of Maryland, College Park & NIST, National Institute of Standards and Technology Center for Neutron Research

  • Jeffrey Simpson

    Towson Univ, Towson University, Physics, Towson University, Department of Physics, Towson University

  • Jiaqiang Yan

    Material Science and Technology Division, Oak Ridge National Lab

  • Stephen E Nagler

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

  • David Mandrus

    Physics, University of Tennessee, Materials Science and Engineering, The University of Tennessee, Department of Materials Science & Engineering, University of Tennessee, Knoxville, The University of Tennesse, Knoxville, University of Tennessee, Department of Physics and Astronomy, University of Tennessee, Oak Ridge National Laboratory, Department of Materials Science and Engineering, University of Tennessee Knoxville, Department of Materials Science and Engineering, University of Tennessee, University of Tennessee, Knoxville, Material Science and Technology Division, Oak Ridge National Laboratory, Material Science and Technology Division, Oak Ridge National Lab

  • Rolando Valdes Aguilar

    Ohio State Univ - Columbus, Ohio State Univ, Physics, The Ohio State University, Ohio State University, Department of Physics, The Ohio State University