{
  "id": "1101.4105",
  "version": "v1",
  "published": "2011-01-21T10:23:14.000Z",
  "updated": "2011-01-21T10:23:14.000Z",
  "title": "Entropic characterization of quantum operations",
  "authors": [
    "Wojciech Roga",
    "Mark Fannes",
    "Karol Zyczkowski"
  ],
  "comment": "21 pages, 4 figures",
  "journal": "International Journal of Quantum Information, 9, pp. 1031 (2011)",
  "categories": [
    "quant-ph"
  ],
  "abstract": "We investigate decoherence induced by a quantum channel in terms of minimal output entropy and of map entropy. The latter is the von Neumann entropy of the Jamiolkowski state of the channel. Both quantities admit q-Renyi versions. We prove additivity of the map entropy for all q. For the case q = 2, we show that the depolarizing channel has the smallest map entropy among all channels with a given minimal output Renyi entropy of order two. This allows us to characterize pairs of channels such that the output entropy of their tensor product acting on a maximally entangled input state is larger than the sum of the minimal output entropies of the individual channels. We conjecture that for any channel {\\Phi}1 acting on a finite dimensional system there exists a class of channels {\\Phi}2 sufficiently close to a unitary map such that additivity of minimal output entropy for {\\Psi}1 x {\\Psi}2 holds.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-01-21T10:23:14.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "minimal output entropy",
      "quantum operations",
      "entropic characterization",
      "quantities admit q-renyi versions",
      "minimal output renyi entropy"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 21,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2011arXiv1101.4105R"
    }
  }
}