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Understanding the Quantum Oscillation Spectrum of Heavy-fermion Compound SmB<sub>6</sub>

ORAL

Abstract

SmB6 is a mysterious compound that is electrically insulating but yet it exhibits quantum oscillations, which are a telltale signature of the metallic state. Adding to the enigma is the possibility that SmB6 is a topological Kondo insulator. Here, we report first-principles, parameter-free all-electron electronic-structure calculations on SmB6, which yield the band structure and crystal-field splittings within the f -electron complex in accord with experiments. Predicted energies of several magnetic phases where charge, spin and lattice degrees of freedom are treated on an equal footing are found to be extremely close, indicating the key role of spin fluctuations in SmB6. Our analysis shows that the topological Kondo state of SmB6 is robust regardless of its magnetic configuration. However, it lies near the metal-insulator transition where the Fermi surface derived from the predicted ground state explains the experimentally observed bulk quantum oscillations. The calculated effective electron mass at the Fermi surface and specific heat further explain how the material is essentially insulating in agreement with the experimental results.

References:
R. Zhang, et al., arXiv:2003.11052
M. Hartstein, et al., Nat. Phys. 14, 166–172 (2018)

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Presenters

  • Ruiqi Zhang

    Tulane Univ, Tulane University

Authors

  • Ruiqi Zhang

    Tulane Univ, Tulane University

  • Bahadur Singh

    Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Department of Condensed Matter Physics and Material Science, Tata Institute of Fundamental Research, Tata Institute of Fundamental Research, Tata Institute for Fundamental Research, DCMPMS, Tata Institute of Fundamental Research, India, Condensed Matter Physics and Material Science, Tata Institute of Fundamental Research, Department of Condensed Matter Physics & Materials Science, Tata Institute of Fundamental Research

  • Christopher Lane

    LANL, Theoretical Division, Los Alamos National Laboratory, Theoretical Division/Center for Integrated Nanotechnology, Los Alamos National Laboratory, Los Alamos National Laboratory

  • Jamin Kidd

    Tulane Univ

  • Yubo Zhang

    Tulane University, Tulane Univ

  • Bernardo Barbiellini

    LUT University, Department of Physics, Lappeenranta University of Technology, Lappeenranta University of Technology, LUT U

  • Robert Markiewicz

    Northeastern University, NU, Northeastern U

  • Arun Bansil

    Department of Physics, Northeastern University, Northeastern University, NU, Department of Physics, Northeastern University, USA

  • Jianwei Sun

    Tulane Univ, Physics, Tulane U., Tulane, Department of Physics and Engineering Physics, Tulane University, Physics and Engineering Physics, Tulane University, Tulane University, Tulane U.