{
  "id": "1802.00099",
  "version": "v1",
  "published": "2018-01-31T23:29:07.000Z",
  "updated": "2018-01-31T23:29:07.000Z",
  "title": "Nonequilibrium Excitations and Transport of Dirac Electrons in Electric-Field-Driven Graphene",
  "authors": [
    "Jiajun Li",
    "Jong E. Han"
  ],
  "comment": "10 pages, 10 figures",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "We investigate nonequilibrium excitations and charge transport in charge-neutral graphene driven with DC electric field by using the nonequilibrium Green's function technique. Due to the vanishing Fermi surface, electrons are subject to non-trivial nonequilibrium excitations such as highly anisotropic momentum distribution of electron-hole pairs, an analog of the Schwinger effect. We show that the electron-hole excitations, initiated by the Landau-Zener tunneling with a superlinear IV relation $I \\propto E^{3/2}$, reaches a steady-state dominated by the dissipation due to optical phonons, resulting in a marginally sublinear IV with $I \\propto E$, in agreement with recent experiments. The linear IV starts to show the sign of current saturation as the graphene is doped away from the Dirac point, and recovers the semi-classical relation for the saturated velocity. We give a detailed discussion on the nonequilibrium charge creation and the relation between the electron-phonon scattering rate and the electric field in the steady-state limit. We explain how the apparent Ohmic IV is recovered near the Dirac point. We propose a mechanism where the peculiar nonequilibrium electron-hole creation can be utilized in a novel infra-red device.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-01-31T23:29:07.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dirac electrons",
      "electric-field-driven graphene",
      "nonequilibrium greens function technique",
      "peculiar nonequilibrium electron-hole creation",
      "dirac point"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}