Evidence for a pressure-induced gapped spin-liquid ground state in a coupled ladder antiferromagnet C<sub>9</sub>H<sub>18</sub>N<sub>2</sub>CuBr<sub>4</sub>

ORAL

Abstract

Here we present a comprehensive study of the effect of hydrostatic pressure on the magnetic structure and spin dynamics in a spin-1/2 coupled ladder antiferromagnet C9H18N2CuBr4 (DLCB for short). In DLCB, the inter-ladder coupling is sufficiently strong to drive the system to the long-range antiferromagnetic ordering phase below TN=2.0 K [1]. Analysis of the spin Hamiltionian suggests that DLCB is close to the quantum critical point in two dimensions at ambient pressure and zero field [2]. The single-crystal heat capacity and neutron diffraction measurements suggets that the magnetic order breaks down above a critical pressure Pc~1.0 GPa. By contrasting with quantum Monte Carlo calculations of the dynamic structure factor, the follow-up inelastic neutron scattering above Pc reveals evidence of a Z2 spin-liquid phase in terms of characteristic fully gapped vison-like and fractionalized excitations in the distinct scattering channels.

References:
[1] Hong et al., Phys. Rev. B 89, 174432 (2014).
[2] Hong et al., Nat. Phys. 13, 638 (2017).

*This research used resources at High Flux Isotope Reactor and Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory (ORNL).

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Presenters

  • Tao Hong

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

Authors

  • Tao Hong

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

  • Tao Ying

    • Harbin Institute of Technology

  • Qing Huang

    • Department of Physics and Astronomy, University of Tennessee, Knoxville
    • University of Tenessee
    • Department of Physics and Astronomy, University of Tennessee
    • National Institute of Standards and Technology
    • University of Tennessee

  • Sachith Dissanayake

    • Department of Physics, Duke University
    • Oak Ridge National Lab
    • Duke University
    • Oak Ridge National Laboratory

  • 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

  • Mark Turnbull

    • Carlson School of Chemistry and Biochemistry and Department of Physics, Clark University
    • Clark University

  • Andrey Podlesnyak

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

  • Yan Wu

    • Oak Ridge National Lab

  • Huibo Cao

    • Oak Ridge National Lab
    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Neutron Scattering, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory

  • Izuru Umehara

    • Yokohama National University

  • Jun Gouchi

    • Institute for Solid State Physics, University of Tokyo
    • Institute for Solid State Physics, The University of Tokyo
    • University of Tokyo

  • Yoshiya Uwatoko

    • Institute for Solid State Physics, University of Tokyo
    • Institute for Solid State Physics, The University of Tokyo
    • University of Tokyo

  • Masaaki Matsuda

    • Oak Ridge National Laboratory
    • Oak Ridge National Lab
    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

  • David A Tennant

    • Oak Ridge National Lab
    • Oak Ridge National Laboratory

  • Kai Schmidt

    • Universitat Erlangen-Nurnberg

  • Stefan Wessel

    • RWTH Aachen University