Spin excitations in single crystal barlowite Cu<sub>4</sub>(OD)<sub>6</sub>FBr—a kagome quantum antiferromagnet

ORAL

Abstract

Barlowite is the parent compound of a new kagome quantum spin liquid candidate Zn-barlowite. We synthesized a new variant of barlowite with a higher symmetry crystal structure at low temperatures. This new high-symmetry barlowite undergoes two consecutive magnetic transitions below ~10 K. Our previous elastic neutron scattering revealed that in the ground state the spins order in a pinwheel q=0 structure, while between the two magnetic transition temperatures the kagome spins likely form a novel valence bond crystal (VBC). In this talk, I will present our recent inelastic neutron scattering data taken on coaligned crystals. The data collected in both the spin ordered and the VBC states exhibit distinct features that cannot be explained by trivial spin waves. Our study provides crucial information regarding the exotic spin excitations in barlowite.

*This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, under contract No. DE-AC02-76SF00515. Access to MACS was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Institute of Standards and Technology and the National Science Foundation under Agreement No. DMR-1508249.

–

Presenters

  • Wei He

    • Materials Science and Engineering, Stanford University
    • SLAC, Stanford

Authors

  • Wei He

    • Materials Science and Engineering, Stanford University
    • SLAC, Stanford

  • Rebecca Smaha

    • Chemistry, Stanford University
    • Applied Physics, Stanford

  • Jiajia Wen

    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory
    • SLAC, Stanford

  • Mingde Jiang

    • Applied Physics, Stanford University
    • Applied Physics, Stanford

  • Yiming Qiu

    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • NIST Center for Neutron research, National Institute of Standards and Technology
    • NIST
    • National Institute of Standards and Technology

  • Young Sang Lee

    • Applied Physics, Stanford University
    • SLAC, Stanford