Interaction Induced Symmetry Breaking in ABA Trilayer Graphene

ORAL

Abstract

We present a mean-field phase diagram of dual-gated ABA trilayer graphene which is obtained by numerically solving the self-consistent Hartree-Fock equations. A metal-insulator phase transition occurs in neutral ABA trilayers at interaction strength $\alpha=0.18$ which is not associated with broken lattice symmetries. ABA trilayers do not possess the inversion symmetry present in bilayers, but do possess a mirror-plane symmetry which remains unbroken for realistic values of alpha for the case of spinless, valley-less fermions. The manner in which SU(4) spin-valley symmetry breaks depends on doping, interlayer bias, and the surrounding dielectric medium. We compare interaction effects in ABA graphene with those in the more familiar chirally-stacked multilayers.

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Authors

  • Rohit Hegde

    University of Texas at Austin

  • Allan MacDonald

    The University of Texas at Austin, Department of Physics, University of Texas at Austin, University of Texas Austin, University of Texas at Austin, Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA