Solitary magnons and orphaned spins in the S=5/2 antiferromagnet CaFe2O4

ORAL

Abstract

CaFe2O4 is a S=5/2 anisotropic antiferromagnet based on zig-zag chains having two competing magnetic structures (denoted as the A and B phases) which differ by the c-axis stacking of ferromagnetic stripes [1]. We apply neutron scattering to demonstrate that the competing orders result in magnetic antiphase boundaries separating these two order parameters at low temperatures. Neutron diffraction and bulk susceptibility find that the spins near these boundaries are weakly correlated and carry an uncompensated moment. Using high resolution neutron spectroscopy, we find that these boundaries are confining and measure a series of 9 quantized spin wave levels at low temperatures [2]. The competing anisotropic order parameters affords both localization of spin waves and also orphan spins in a classical magnet.
[1] L. M. Corliss et al. Phys. Rev. 160, 408 (1967).
[2] C. Stock et al. Phys. Rev. Lett. 117, 017201 (2016).

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Presenters

  • Chris Stock

    University of Edinburgh, Univ of Edinburgh, University of Edingburgh, The University of Edinburgh, Physics , The University of Edinburgh

Authors

  • Chris Stock

    University of Edinburgh, Univ of Edinburgh, University of Edingburgh, The University of Edinburgh, Physics , The University of Edinburgh

  • Efrain Rodriguez

    University of Maryland, Department of Chemistry and Biochemistry, University of Maryland, Chemistry and Biochemistry , University of Maryland

  • Franz Demmel

    ISIS Facility, ISIS Facility, Rutherford Appleton Laboratory, ISIS Neutron Source

  • Russell Ewings

    ISIS Facility

  • Ch. Niedermayer

    Laboratory for Neutron Scattering, Paul Scherrer Institute, Paul Scherrer Institute

  • Yixi Su

    Julich Centre for Neutron Science, Jülich Centre for Neutron Science at MLZ, Forschungszentrum Jülich GmbH

  • Jose Rodriguez

    NIST, NIST Center for Neutron research, NCNR, NIST, NIST NCNR, NIST Center for Neutron Research

  • Sang-Wook Cheong

    Rutgers University, Department of Physics and Astronomy, Rutgers University, Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Physics, Rutgers University, Physics and Astronomy, Rutgers University, Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Physics and Astronomy, Rutgers Univ., Rutgers Univ, Physics, Rutgers Univesity, Department of Physics, Rutgers University, Physics and Astronomy, Rutgers Center for Emergent Materials, Department of Physics & Astronomy , Rutgers University

  • K. Nemkovski

    Julich Centre for Neutron Science

  • Mark Laver

    University of Birmingham, Birmingham University