Quantum Spin Chain Dynamics in YbAlO<sub>3</sub> Perovskite

ORAL

Abstract

Here, we demonstrate experimentally and confirm by theoretical calculations that rare-earth perovskite YbAlO3 is an excellent experimental realization of an effective spin-1/2 quantum XXZ chain. Inelastic neutron scattering spectra taken on YbAlO3 provide evidence for unconventional low-energy magnetic excitations. The spectrum at temperatures above antiferromagnetic ordering TN=0.8K is characterized by a gapless continuum with dispersive boundaries in one direction and bandwidth of ΔE~0.6meV at the zone center. Cooling down through the TN, a different spectrum emerges. A gap is opened abruptly and the excitation spectrum is dominated by a high-intensity sharp mode. The observed excitations have negligible dispersion along the other directions, proving our conclusion that the Yb moments form weakly coupled spin chains despite the three-dimensional perovskite structure. We also argue that the series of rare-earth based perovskites could be an exceptional candidate for low dimensional S=1/2 quantum chain with tunable intrinsic parameters to explore quantum magnetism.

*This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.

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Presenters

  • Andrei Podlesnyak

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

Authors

  • Andrei Podlesnyak

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

  • L.S. Wu

    • Oak Ridge National Lab

  • Zhentao Wang

    • Physics, University of Tennessee
    • The University of Tennessee
    • Univ of Tennessee, Knoxville

  • W. Zhu

    • Los Alamos National Laboratory
    • Los Alamos Natl Lab

  • S.E. Nikitin,

    • Max Planck Institute for Chemical Physics of Solids

  • Cristian Batista

    • Department of Physics and Astronomy, Univ of Tennessee, Knoxville
    • Univ of Tennessee, Knoxville
    • Department of Physics and Astronomy, The University of Tennessee
    • University of Tennessee
    • Physics, University of Tennessee
    • The University of Tennessee
    • Department of Phys., Univ. of Tennessee
    • U. Tennessee, Knoxville
    • University of Tennessee, Knoxville

  • G. Ehlers

    • Neutron Technologies Division, Oak Ridge National Laboratory
    • ORNL-Spallation Neutron Source
    • Oak Ridge National Lab
    • QCMD, Oak Ridge National Laboratory

  • Mark Lumsden

    • Oak Ridge National Lab

  • L. Vasylechko

    • Lviv Polytechnic National University