Magnetic field dependence of magnetic correlations in a pyrochlore Heisenberg antiferromagnet

ORAL

Abstract

Recent neutron experiments on the S=1 pyrochlore NaCaNi2F7 [1] revealed a dynamic structure factor exhibiting pinch points and a continuum of high energy magnetic excitations. These signatures point towards a magnetic ground-state which can be described by an almost ideal Heisenberg antiferromagnet on the pyrochlore lattice. Although a highly degenerate ground state its expected at low temperatures, disorder freezes the spin degrees of freedom so that a specific spin configuration is preferred [2]. How disorder induces a frozen spin state in this Coulomb phase [3] remains to be fully understood. We present here a set of neutron scattering measurements in NaCaNi2F7 as a function of external magnetic field. Above a threshold field, H > 2 T, a long-range ordered magnetic field polarized phase emerges. I will discuss the magnetic field and temperature evolution of magnetic correlations in NaCaNi2F7 through this polarized phase.

[1] Krizan, J. W. and Cava, R. J., Physical Review B 92, 014406 (2015)
[2] Plumb, K. W. et al, Nat. Phys. 1, 54 (2019)
[3] Henley, C. L., Annu. Rev. Condens. Matter Phys 1, 179 (2010)

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Presenters

  • Alberto De la Torre

    • Caltech
    • Brown University

Authors

  • Alberto De la Torre

    • Caltech
    • Brown University

  • Jason W. Krizan

    • Princeton Univ
    • Princeton University

  • Guangyong Xu

    • Center of Neutron Research, National Institute of Standards and Technology
    • Neutron-Condensed Matter Science Group, National Institute of Standards and Technology
    • National Institute of Standards and Technology
    • NIST
    • Center for Neutron Research, National Institute of Standards and Technology
    • NIST Center for Neutron Research
    • Oak Ridge National Laboratory

  • Robert J. Cava

    • Princeton University
    • Chemistry, Princeton University
    • Department of Chemistry, Princeton University
    • Chemistry, Pinceton University
    • Princeton Univ

  • Kemp Plumb

    • Brown University