Collective Excitations in the Frustrated Classical Spin Liquid MgCr2O4

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