{
  "id": "1107.5931",
  "version": "v1",
  "published": "2011-07-29T11:09:27.000Z",
  "updated": "2011-07-29T11:09:27.000Z",
  "title": "Fidelity spectrum and phase transitions of quantum systems",
  "authors": [
    "P. D. Sacramento",
    "N. Paunkovic",
    "V. R. Vieira"
  ],
  "comment": "12 figures",
  "journal": "Physical Review A 84, 062318 (2011)",
  "categories": [
    "quant-ph",
    "cond-mat.supr-con"
  ],
  "abstract": "Quantum fidelity between two density matrices, $F(\\rho_1,\\rho_2)$ is usually defined as the trace of the operator ${\\cal F}=\\sqrt{\\sqrt{\\rho_1} \\rho_2 \\sqrt{\\rho_1}}$. We study the logarithmic spectrum of this operator, which we denote by {\\it fidelity spectrum}, in the cases of the $XX$ spin chain in a magnetic field, a magnetic impurity inserted in a conventional superconductor and a bulk superconductor at finite temperature. When the density matrices are equal, $\\rho_1=\\rho_2$, the fidelity spectrum reduces to the entanglement spectrum. We find that the fidelity spectrum can be a useful tool in giving a detailed characterization of different phases of many-body quantum systems.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-07-29T11:09:27.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "03.67.-a",
      "05.70.Fh",
      "74.20.Fg"
    ],
    "keywords": [
      "phase transitions",
      "density matrices",
      "many-body quantum systems",
      "fidelity spectrum reduces",
      "entanglement spectrum"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review A",
      "doi": "10.1103/PhysRevA.84.062318",
      "year": 2011,
      "month": "Dec",
      "volume": 84,
      "number": 6,
      "pages": "062318"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2011PhRvA..84f2318S"
    }
  }
}