{
  "id": "1103.3650",
  "version": "v2",
  "published": "2011-03-18T15:38:00.000Z",
  "updated": "2011-04-11T16:40:05.000Z",
  "title": "Screening effects on the excitonic instability in graphene",
  "authors": [
    "J. Gonzalez"
  ],
  "comment": "4 pages, 2 figures, more references added",
  "doi": "10.1103/PhysRevB.85.085420",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.str-el"
  ],
  "abstract": "We investigate the excitonic instability in the theory of Dirac fermions in graphene with long-range Coulomb interaction. We analyze the electron-hole vertex relevant for exciton condensation in the ladder approximation, showing that it blows up at a critical value of the interaction strength \\alpha = e^2/4\\pi v_F sensitive to further many-body corrections. Under static screening of the interaction, we find that taking into account electron self-energy corrections increases the critical coupling to \\alpha_c \\approx 2.09, for a number N = 4 of two-component Dirac fermions. We show that the dynamical screening of the interaction has however the opposite effect of enhancing the instability, which turns out to develop then at \\alpha_c \\approx 0.99 for N = 4, bringing the question of whether that critical value can be reached by the effective coupling in real graphene samples at the low-energy scales of the exciton condensation.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2011-04-11T16:40:05.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "71.10.Pm",
      "11.10.Gh",
      "71.30.+h",
      "72.80.Vp"
    ],
    "keywords": [
      "excitonic instability",
      "screening effects",
      "account electron self-energy corrections increases",
      "exciton condensation",
      "critical value"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review B",
      "year": 2012,
      "month": "Feb",
      "volume": 85,
      "number": 8,
      "pages": "085420"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 901463,
      "adsabs": "2012PhRvB..85h5420G"
    }
  }
}