Observation of Two Magnetically Inequivalent Regions in SmB6 at Low Temperatures

ORAL

Abstract

The temperature dependence of the μSR relaxation rate in SmB6 exposed to a high transverse magnetic field (TF) was recently shown to exhibit thermally-activated behavior for 4 K < T < 20 K, consistent with the freezing out of a bulk low-energy (~ 1 meV) spin exciton [K. Akintola et al., npj Quantum Materials 3:36 (2018)]. However, a 1 meV magnetic excitation has never been observed in neutron scattering measurements, all of which have been performed on the same floating-zone grown double-isotope 154Sm11B6 single crystal. In an attempt to understand why, we have performed zero-field (ZF) and longitudinal-field (LF) μSR measurements on the 154Sm11B6 and Al-flux grown SmB6 single crystals. The μSR signals show greater relaxation in the 154Sm11B6 single crystal, and reveal the development of slow and fast relaxing components below T ~ 20 K. The volume fraction of the slower relaxing component grows to ~ 70 % at T = 2 K. While the relaxation rates are smaller, the volume fractions of the two components are similar in the Al-flux grown SmB6 crystals. This suggests that the source of the two components is intrinsic and originates from spatially distinguishable regions in the sample.

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Presenters

  • Jeff Sonier

    Department of Physics, Simon Fraser University, Simon Fraser University

Authors

  • Jeff Sonier

    Department of Physics, Simon Fraser University, Simon Fraser University

  • Kolawole Akintola

    Department of Physics, Simon Fraser University, Simon Fraser University

  • Shayan Gheidi

    Department of Physics, Simon Fraser University, Simon Fraser University

  • Sarah R Dunsiger

    TRIUMF

  • Andre Cote

    Kwantlen Polytechnic University

  • Shanta Saha

    Physics, University of Maryland, Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, University of Maryland, College Park & NIST, Department of Physics, University of Maryland, College Park, University of Maryland, University of Maryland - College Park

  • Johnpierre Paglione

    Physics, University of Maryland, University of Maryland, College Park, Center for Nanophysics and Advanced Materials, University of Maryland College Park, Center for Nanophysics and Advance Materials, University of Maryland, College Park, MD, University of Maryland, College Park & NIST, Department of Physics, University of Maryland, College Park, University of Maryland, University of Maryland - College Park

  • Wesley T Fuhrman

    Institute for Quantum Matter, Johns Hopkins University, Department of Physics and Astronomy, Johns Hopkins University, Johns Hopkins University

  • Collin Broholm

    Johns Hopkins, Johns Hopkins University, IQM, Johns Hopkins University, Department of Physics and Astronomy, Johns Hopkins University