{
  "id": "cond-mat/0109266",
  "version": "v2",
  "published": "2001-09-14T11:40:30.000Z",
  "updated": "2001-09-19T09:54:57.000Z",
  "title": "Ferromagnetism and Transport in the Double-Exchange Model, with and without Phonons; Application to the Manganites",
  "authors": [
    "D. M. Edwards",
    "A. C. M. Green"
  ],
  "comment": "26 pages, 14 figures",
  "categories": [
    "cond-mat.str-el",
    "cond-mat.mtrl-sci"
  ],
  "abstract": "An introduction is given to the many-body coherent potential approximation (CPA) for the double-exchange (DE) model and the Holstein-DE model, the latter including coupling of the electrons to local phonons as well as to local spins. It is shown how the method can treat the local spins and phonons quantum-mechanically and how it is equivalent to dynamical mean field theory in the classical limit. In the Holstein-DE model a full discussion is given of the cross-over from weak electron-phonon coupling through intermediate coupling, where small-polaron bands begin to appear, to strong coupling where some results similar to those of standard small-polaron theory are recovered. The theory is applied to ferromagnetic manganites with a full discussion of magnetic, transport and spectroscopic data. It is found that many manganites are in the critical regime on the verge of small-polaron formation, which explains their sensitivity to parameters such as applied magnetic field and pressure.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2001-09-19T09:54:57.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "double-exchange model",
      "manganites",
      "holstein-de model",
      "application",
      "many-body coherent potential approximation"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 26,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2001cond.mat..9266E"
    }
  }
}