{
  "id": "2009.14594",
  "version": "v1",
  "published": "2020-09-30T12:15:49.000Z",
  "updated": "2020-09-30T12:15:49.000Z",
  "title": "Anomalous conductivity of two-dimensional Dirac electrons in organic conductor under pressures",
  "authors": [
    "Yoshikazu Suzumura",
    "Masao Ogata"
  ],
  "comment": "9 pages, 16 figures",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "Dirac electrons in organic conductor $\\alpha$-(BEDT-TTF)$_2$I$_3$ under pressures, which exhibit anomalous conductivity being nearly constant at high temperatures, have been examined using a two-dimensional tight-binding model (TB) model with both the impurity and electron-phonon (e-p) scatterings. A crucial role of scattering by acoustic phonon is shown based on the previous study for a model with simple Dirac cone [Phys. Rev. B {\\bf 98},161205 (2018)]. In addition to diagonal conductivity $\\sigma_{x}=\\sigma_{xx}$ and $\\sigma_{y}=\\sigma_{yy}$, off-diagonal conductivity $\\sigma_{xy}$ exists due to a tilted Dirac cone, where $y$ ($x$) corresponds to a direction parallel (perpendicular) to a stacking axis of molecules. This $\\sigma_{xy}$ results in a rotation of axis of the principal value $\\sigma_{\\pm}$. Since the conductivity at high temperatures is suppressed by the e-p scattering on the Dirac cone, the increase of temperature results in a broad maximum for $\\sigma_y$ and a nearly constant $\\sigma_x$ for a moderate choice of the e-p coupling constant. Further a correlation effect is examined employing a mean-field for the on-site and nearest-neighbor-site interactions. Anisotropic behavior of $\\sigma_{\\nu}$, ($\\nu$ = $x$ and $y$) is discussed by comparing with experiments of organic conductors, which present nearly constant resistivity at high temperatures.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-09-30T12:15:49.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "organic conductor",
      "two-dimensional dirac electrons",
      "anomalous conductivity",
      "high temperatures",
      "simple dirac cone"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}