{
  "id": "1103.5592",
  "version": "v1",
  "published": "2011-03-29T10:24:59.000Z",
  "updated": "2011-03-29T10:24:59.000Z",
  "title": "Quantum receiver beyond the standard quantum limit of coherent optical communication",
  "authors": [
    "Kenji Tsujino",
    "Daiji Fukuda",
    "Go Fujii",
    "Shuichiro Inoue",
    "Mikio Fujiwara",
    "Masahiro Takeoka",
    "Masahide Sasaki"
  ],
  "comment": "5 pages, 3 figures",
  "journal": "Phys. Rev. Lett. 106, 250503 (2011)",
  "categories": [
    "quant-ph"
  ],
  "abstract": "The most efficient modern optical communication is known as coherent communication and its standard quantum limit (SQL) is almost reachable with current technology. Though it has been predicted for a long time that this SQL could be overcome via quantum mechanically optimized receivers, such a performance has not been experimentally realized so far. Here we demonstrate the first unconditional evidence surpassing the SQL of coherent optical communication. We implement a quantum receiver with a simple linear optics configuration and achieve more than 90% of the total detection efficiency of the system. Such an efficient quantum receiver will provide a new way of extending the distance of amplification-free channels, as well as of realizing quantum information protocols based on coherent states and the loophole-free test of quantum mechanics.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-03-29T10:24:59.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "03.67.Hk",
      "42.50.Ex"
    ],
    "keywords": [
      "standard quantum limit",
      "coherent optical communication",
      "simple linear optics configuration",
      "first unconditional evidence",
      "total detection efficiency"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review Letters",
      "doi": "10.1103/PhysRevLett.106.250503",
      "year": 2011,
      "month": "Jun",
      "volume": 106,
      "number": 25,
      "pages": 250503
    },
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2011PhRvL.106y0503T"
    }
  }
}