Topological phase transitions with SO(4) symmetry in (2+1)d interacting Dirac fermions

ORAL

Abstract

Interaction-driven topological phase transitions in Dirac semimetals are investigated by means of large-scale quantum Monte Carlo (QMC) simulations. The interaction among Dirac fermions is introduced by coupling them to Ising spins that realize the quantum dynamics of the two-dimensional transverse field Ising model. The ground state phase diagram, in which the tuning parameters are the transverse field and the coupling between fermion and Ising spins, is determined. At weak and intermediate coupling, a second-order Ising quantum phase transition and a first-order topological phase transition between two topologically distinct Dirac semimetals are observed. Interestingly, at the latter, the Dirac points smear out to form nodal lines in the Brillouin zone, and collective bosonic fluctuations with SO(4) symmetry are strongly enhanced. At strong coupling, these two phase boundaries merge into a first-order transition.

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Authors

  • Xiao Yan Xu

    Institute of Physics, Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Institute of Physics,Chinese Academy of Sciences

  • K. S. D. Beach

    Univ of Mississippi, The University of Mississippi, Department of Physics and Astronomy, The University of Mississippi

  • Kai Sun

    University of Michigan, Univ of Michigan - Ann Arbor, University of Michigan, Ann Arbor, Department of Physics, University of Michigan, Ann Arbor, Department of Physics, University of Michigan

  • F. F. Assaad

    Universität Würzburg, Institut fuer Theoretische Physik und Astrophysik,Universitat Wuerzburg, 97074 Wuerzburg, Germany, Institut für Theoretische Physik und Astrophysik, Universität Würzburg

  • Zi Yang Meng

    Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China, Institute of Physics, Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Institute of Physics, Chinese Academy of Sciences, Beijing, Institute of Physics,Chinese Academy of Sciences