Formation of magnetic order in the Kitaev-Heisenberg model

ORAL

Abstract

We compute the low-energy excitation spectrum and the dynamical magnetic spin structure factor of the Kitaev-Heisenberg model using a variational approach, that becomes exact at the exactly solvable Kitaev points. This approach reveals the physical origin of the asymmetry in the stability range of Kitaev spin liquid phases around the ferromagnetic and antiferromagnetic Kitaev points. We also show that bound states of fractionalized excitations appear in the proximity of a quantum phase transition between the ferrmagnetic Kitaev spin spin liquid and the magnetically ordered states induced by ferro and antiferromagnetic Heisenberg interactions.

*S.~Z. and C.~D.~B. are supported by funding from the Lincoln Chair of Excellence in Physics and from the Los Alamos National Laboratory
Directed Research and Development program. G.~B.~H. is supported by the Gordon and Betty Moore Foundation's EPiQS Initiative through
Grant No.~GBMF4304. W. Z. was supported by DOE National Nuclear Security Administration through Los Alamos National Laboratory LDRD Program.

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Presenters

  • Shang-Shun Zhang

    • Department of Physics and Astronomy, The University of Tennessee
    • University of Tennessee

Authors

  • Shang-Shun Zhang

    • Department of Physics and Astronomy, The University of Tennessee
    • University of Tennessee

  • Gabor Halasz

    • Oak Ridge National Laboratory
    • Oakridge National Laboratory
    • Oak Ridge National Liboratory

  • Wei Zhu

    • Los Alamos National Laboratory

  • Cristian Batista

    • Department of Physics & Astronomy, University of Tennessee, Knoxville, TN 37996, USA
    • Department of Physics and Astronomy, The University of Tennessee
    • University of Tennessee
    • Department of Physics and Astronomy, University of Tennessee
    • Department of Physics, University of Tennessee