{
  "id": "0802.3896",
  "version": "v2",
  "published": "2008-02-27T01:30:28.000Z",
  "updated": "2008-06-03T20:03:59.000Z",
  "title": "Optimal tracking for pairs of qubit states",
  "authors": [
    "Paulo E. M. F. Mendonca",
    "Alexei Gilchrist",
    "Andrew C. Doherty"
  ],
  "comment": "15 pages, 8 figures. Extensive revision of text, optimality results extended, other physical applications included",
  "journal": "Phys. Rev. A, 78, 012319 (2008)",
  "doi": "10.1103/PhysRevA.78.012319",
  "categories": [
    "quant-ph"
  ],
  "abstract": "In classical control theory, tracking refers to the ability to perform measurements and feedback on a classical system in order to enforce some desired dynamics. In this paper we investigate a simple version of quantum tracking, namely, we look at how to optimally transform the state of a single qubit into a given target state, when the system can be prepared in two different ways, and the target state depends on the choice of preparation. We propose a tracking strategy that is proved to be optimal for any input and target states. Applications in the context of state discrimination, state purification, state stabilization and state-dependent quantum cloning are presented, where existing optimality results are recovered and extended.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2008-06-03T20:03:59.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "03.67.Pp",
      "03.65.Ta"
    ],
    "keywords": [
      "qubit states",
      "optimal tracking",
      "target state depends",
      "classical control theory",
      "single qubit"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review A",
      "year": 2008,
      "month": "Jul",
      "volume": 78,
      "number": 1,
      "pages": "012319"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2008PhRvA..78a2319M"
    }
  }
}