{
  "id": "1208.3042",
  "version": "v1",
  "published": "2012-08-15T06:35:23.000Z",
  "updated": "2012-08-15T06:35:23.000Z",
  "title": "Missing derivative discontinuity of the exchange-correlation energy for attractive interactions: the charge Kondo effect",
  "authors": [
    "E. Perfetto",
    "G. Stefanucci"
  ],
  "comment": "5 pages, 5 eps figure. Phys. Rev. B 86, 081409(R) (2012)",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "We show that the energy functional of ensemble Density Functional Theory (DFT) [Perdew et al., Phys. Rev. Lett. 49, 1691 (1982)] in systems with attractive interactions is a convex function of the fractional particle number N and is given by a series of straight lines joining a subset of ground-state energies. As a consequence the exchange-correlation (XC) potential is not discontinuous for all N. We highlight the importance of this exact result in the ensemble-DFT description of the negative-U Anderson model. In the atomic limit the discontinuity of the XC potential is missing for odd N while for finite hybridizations the discontinuity at even N is broadened. We demonstrate that the inclusion of these properties in any approximate XC potential is crucial to reproduce the characteristic signatures of the charge-Kondo effect in the conductance and charge susceptibility.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2012-08-15T06:35:23.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "71.15.Mb",
      "05.60.Gg",
      "31.15.E-",
      "72.10.Fk"
    ],
    "keywords": [
      "charge kondo effect",
      "missing derivative discontinuity",
      "attractive interactions",
      "exchange-correlation energy",
      "fractional particle number"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1103/PhysRevB.86.081409",
      "journal": "Physical Review B",
      "year": 2012,
      "month": "Aug",
      "volume": 86,
      "number": 8,
      "pages": "081409"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2012PhRvB..86h1409P"
    }
  }
}