Phase diagram of the spin-1/2 Kitaev-Gamma chain and emergent ``partial" SU(2) symmetry

ORAL

Abstract

We study the phase diagram of a one-dimensional version of the Kitaev spin-1/2 model with an extra ``$\Gamma$-term", using analytical, density matrix renormalization group and exact diagonalization methods. Two intriguing phases are found. In the gapless phase, the low energy theory is described by an emergent SU(2)$_1$ Wess-Zumino-Witten (WZW) model though the exact symmetry group is discrete. On the other hand, the relations between the local spin operators and the WZW currents and primary field contain SU(2) breaking coefficients. A modified nonabelian bosonization formula is proposed to capture such exotic emergent ``partial" SU(2) symmetry. In the ordered phase, there is numerical evidence for an $O_h\rightarrow D_8$ spontaneous symmetry breaking.

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Presenters

  • Wang Yang

    • Physics, University of British Columbia

Authors

  • Wang Yang

    • Physics, University of British Columbia

  • Alberto Nocera

    • Physics, University of British Columbia

  • Tarun Tummuru

    • Physics, University of British Columbia

  • Hae-Young Kee

    • University of Toronto
    • Physics, University of Toronto
    • Univ of Toronto

  • Ian Affleck

    • Physics and Astronomy, University of British Columbia
    • Department of Physics and Astronomy and Stewart Blusson Quantum Matter Institute, University of British Columbia
    • Physics, University of British Columbia
    • University of British Columbia