{
  "id": "2401.12528",
  "version": "v1",
  "published": "2024-01-23T07:08:07.000Z",
  "updated": "2024-01-23T07:08:07.000Z",
  "title": "Landau-Level Mixing and SU(4) Symmetry Breaking in Graphene",
  "authors": [
    "Nemin Wei",
    "Guopeng Xu",
    "Inti Sodemann Villadiego",
    "Chunli Huang"
  ],
  "comment": "Main text: 4 Pages, 2 figures; Supplementary Material: 9 Pages, 5 figures",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.str-el"
  ],
  "abstract": "Recent scanning tunneling microscopy experiments on graphene at charge neutrality under strong magnetic fields have uncovered a ground state characterized by Kekul\\'e distortion (KD). In contrast, non-local spin and charge transport experiments in double-encapsulated graphene, which has a higher dielectric constant, have identified an antiferromagnetic (AF) ground state. We propose a mechanism to reconcile these conflicting observations, by showing that Landau-level mixing can drive a transition from AF to KD with the reduction of the dielectric screening. Our conclusion is drawn from studying the effect of Landau-level mixing on the lattice-scale, valley-dependent interactions to leading order in graphene's fine structure constant $\\kappa = e^2/(\\hbar v_F \\epsilon)$. This analysis provides three key insights: 1) Valley-dependent interactions remain predominantly short-range with the $m=0$ Haldane pseudopotential being at least an order of magnitude greater than the others, affirming the validity of delta-function approximation for these interactions. 2) The phase transition between the AF and KD states is driven by the microscopic process in the double-exchange Feynman diagram. 3) The magnitudes of the coupling constants are significantly boosted by remote Landau levels. Our model also provides a theoretical basis for numerical studies of fractional quantum Hall states in graphene.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-01-23T07:08:07.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "landau-level mixing",
      "symmetry breaking",
      "ground state",
      "graphenes fine structure constant",
      "valley-dependent interactions remain predominantly short-range"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}