{
  "id": "1202.1598",
  "version": "v2",
  "published": "2012-02-08T04:21:01.000Z",
  "updated": "2013-06-24T04:38:01.000Z",
  "title": "Quantifying non-classicality with local unitary operations",
  "authors": [
    "Sevag Gharibian"
  ],
  "comment": "8 pages, comments welcome. v2: Minor updates to match the published version",
  "journal": "Physical Review A, 86:042106, 2012",
  "doi": "10.1103/PhysRevA.86.042106",
  "categories": [
    "quant-ph"
  ],
  "abstract": "We propose a measure of non-classical correlations in bipartite quantum states based on local unitary operations. We prove the measure is non-zero if and only if the quantum discord is non-zero; this is achieved via a new characterization of zero discord states in terms of the state's correlation matrix. Moreover, our scheme can be extended to ensure the same relationship holds even with a generalized version of quantum discord in which higher-rank projective measurements are allowed. We next derive a closed form expression for our scheme in the cases of Werner states and (2 x N)-dimensional systems. The latter reveals that for (2 x N)-dimensional states, our measure reduces to the geometric discord [Dakic et al., PRL 105, 2010]. A connection to the CHSH inequality is shown. We close with a characterization of all maximally non-classical, yet separable, (2 x N)-dimensional states of rank at most two (with respect to our measure).",
  "revisions": [
    {
      "version": "v2",
      "updated": "2013-06-24T04:38:01.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "03.65.Ud",
      "03.65.Ta",
      "03.67.Ac",
      "03.67.Mn"
    ],
    "keywords": [
      "local unitary operations",
      "quantifying non-classicality",
      "quantum discord",
      "bipartite quantum states",
      "zero discord states"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review A",
      "year": 2012,
      "month": "Oct",
      "volume": 86,
      "number": 4,
      "pages": "042106"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 8,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2012PhRvA..86d2106G"
    }
  }
}