Weakly-coupled alternating <i>S</i>=1/2 chains in the distorted honeycomb-lattice compound Na<sub>2</sub>Cu<sub>2</sub>TeO<sub>6</sub>

ORAL

Abstract

Spin-1/2 chains with alternating antiferromagnetic (AF) and ferromagnetic (FM) couplings exhibit quantum entanglement like the integer-spin Haldane chains and might be similarly utilized for quantum computations. Such alternating AF-FM chains have been proposed to be realized in the distorted honeycomb-lattice compound Na2Cu2TeO6, but ambiguities remain as to the coupling strengths. Here we employ neutron scattering to study the spin dynamics in Na2Cu2TeO6 and accurately determine the coupling strengths through the random phase approximation and density functional theory (DFT) approaches. We find the AF and FM intrachain couplings are the dominant terms in the spin Hamiltonian, while the interchain couplings are AF but perturbative, thus establishing Na2Cu2TeO6 as a weakly-coupled alternating AF-FM chain compound. The hierarchy in the coupling strengths and the alternating signs of the intrachain couplings can be understood through their different exchange paths.

S. Gao et al. arXiv2010.06745 (2020)

*Research supported by the U. S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by Oak Ridge National Laboratory.

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Presenters

  • Shang Gao

    • Oak Ridge National Lab

Authors

  • Shang Gao

    • Oak Ridge National Lab

  • Ling-Fang Lin

    • University of Tennessee

  • Andrew May

    • Oak Ridge National Laboratory
    • Oak Ridge National Lab
    • Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

  • Binod K Rai

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

  • Qiang Zhang

    • Oak Ridge National Laboratory
    • SNS, Oak Ridge National Laboratory
    • Oak Ridge National Lab

  • Elbio Dagotto

    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennesse at Knoxville
    • Physics, University of Tennessee
    • University of Tennessee and ORNL
    • Department of Physics and Astronomy, University of Tennessee
    • Oak Ridge National Lab

  • Andrew Christianson

    • Oak Ridge National Lab
    • Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Oak Ridge National Laboratory

  • Matthew Brandon Stone

    • Oak Ridge National Lab
    • Oak Ridge national lab
    • Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Oakridge National Laboratory