Neutron scattering investigation of proposed Kosterlitz-Thouless transitions in the triangular-lattice Ising antiferromagnet TmMgGaO<sub>4</sub>

ORAL

Abstract

The transverse-field Ising model on the triangular lattice is expected to host an intermediate Kosterlitz-Thouless (KT) phase through a mapping from spins to a complex order parameter residing on each triangular unit. TmMgGaO4 is a candidate material to realize such physics due to the non-Kramers nature of the Tm3+ ion and two-singlet single-ion ground state. Using inelastic neutron scattering, we confirm this picture by determining the leading parameters of the low-energy effective Hamiltonian. Subsequently, we track the predicted KT phase by inspecting the field and temperature dependence of the ac susceptibility, and spin correlations in both reciprocal space and real space via single-crystal neutron diffraction and magnetic total scattering techniques, respectively. Around 4 K, magnetic pair distribution function analysis provides evidence for the vortex anti-vortex pairs that characterize the proposed Kosterlitz-Thouless phase. Although structural disorder plays a significant role in the field-induced behavior of TmMgGaO4, the magnetism in zero-field appears relatively free from these effects. TmMgGaO4 is thus a rare example of a dense spin system for which continuous phase transitions can be investigated and controlled.

*The work at Gatech is supported by NSF-DMR-1750186.

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Presenters

  • Zhiling Dun

    • Georgia Institute of Technology
    • School of Physics, Georgia Institute of Technology

Authors

  • Zhiling Dun

    • Georgia Institute of Technology
    • School of Physics, Georgia Institute of Technology

  • Marcus J Daum

    • Georgia Institute of Technology

  • Raju Baral

    • Physics and Astronomy, Brigham Young University
    • Department of Physics, Brigham Young University
    • Brigham Young University

  • Henry Edward Fischer

    • Institut Laue-Langevin

  • Huibo Cao

    • Oak Ridge National Lab
    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Neutron Scattering, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory

  • Yaohua Liu

    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Lab
    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory

  • Matthew Brandon Stone

    • Oak Ridge National Lab
    • Oak Ridge national lab
    • Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Oakridge National Laboratory

  • 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

  • Eun Sang Choi

    • National High Magnetic Field Laboratory, Florida State University
    • National High Magnetic Field Laboratory
    • National High Magnetic Field Laboratory and Department of Physics, Florida State University
    • National High Magnetic Field Lab
    • Physics, Florida State University
    • National High Field Magnet Laboratory
    • Florida Sate University

  • Qing Huang

    • Department of Physics and Astronomy, University of Tennessee, Knoxville
    • University of Tenessee
    • Department of Physics and Astronomy, University of Tennessee
    • National Institute of Standards and Technology
    • University of Tennessee

  • Haidong Zhou

    • Dep. Physics and Astronomy, University of Tennessee, Knoxville TN
    • Department of Physics and Astronomy, University of Tennessee, Knoxville
    • University of Tenessee
    • University of Tennessee, Knoxville
    • Physics and Astronomy, University of Tennessee at Knoxville
    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennessee

  • Martin P Mourigal

    • Georgia Institute of Technology
    • Georgia Inst of Tech
    • School of Physics, Georgia Institute of Technology

  • Benjamin Frandsen

    • Physics and Astronomy, Brigham Young University
    • Department of Physics, Brigham Young University
    • Brigham Young University
    • Department of Physics and Astronomy, Brigham Young University