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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).

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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