APS Logo

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)

–

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