Collective Excitations in the Frustrated Classical Spin Liquid MgCr<sub>2</sub>O<sub>4</sub>

ORAL

Abstract

Frustrated magnetic materials are of fundamental interest because they show exotic properties that arise from competing constraints; e.g., suppression of conventional magnetic order and sensitivity of the ground state to perturbations. The spinel MgCr2O4 is a canonical example of a highly-frustrated antiferromagnet in which Heisenberg spins occupy a pyrochlore lattice of corner-sharing tetrahedra. Magnetic frustration is demonstrated by the suppression of the magnetic ordering temperature compared to the Weiss constant and broad magnetic excitations resembling emergent hexagonal spin-loops. We present a comprehensive single crystal inelastic neutron scattering study of this material in the spin liquid regime based on a classical Heisenberg model. The dynamical structure factor is simulated in the framework of spin-wave theory and shows excellent agreement with the experimental data.

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Presenters

  • XIAOJIAN BAI

    • Physics, Georgia Inst of Tech

Authors

  • XIAOJIAN BAI

    • Physics, Georgia Inst of Tech

  • Eliot Kapit

    • Physics and Engineering Physics, Tulane University
    • Tulane University
    • Department of Physics & Engineering Physics, Tulane University

  • Joseph Paddison

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

  • Jiajia Wen

    • Stanford University
    • SLAC National Accelerator Laboratory

  • Seyed Koohpayeh

    • Johns Hopkins University
    • The Johns Hopkins University

  • Garrett Granroth

    • Oak Ridge National Laboratory

  • Alexander Kolesnikov

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

  • Tyrel McQueen

    • Johns Hopkins University
    • Institute for Quantum Matter, Johns Hopkins University
    • Department of Chemistry , Johns Hopkins University
    • The Johns Hopkins University

  • John Chalker

    • Oxford University

  • Collin Broholm

    • Johns Hopkins University
    • Institute for Quantum Matter, Johns Hopkins University

  • Martin Mourigal

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