{
  "id": "quant-ph/0410072",
  "version": "v1",
  "published": "2004-10-11T13:54:35.000Z",
  "updated": "2004-10-11T13:54:35.000Z",
  "title": "Experimental demonstration of quantum memory for light",
  "authors": [
    "Brian Julsgaard",
    "Jacob Sherson",
    "J. Ignacio Cirac",
    "Jaromir Fiurasek",
    "Eugene S. Polzik"
  ],
  "comment": "22 pages (double line spacing) incl. supplementary information, 4 figures, accepted for publication in Nature",
  "journal": "Nature 432, 482 - 486 (25 November 2004)",
  "doi": "10.1038/nature03064",
  "categories": [
    "quant-ph"
  ],
  "abstract": "The information carrier of today's communications, a weak pulse of light, is an intrinsically quantum object. As a consequence, complete information about the pulse cannot, even in principle, be perfectly recorded in a classical memory. In the field of quantum information this has led to a long standing challenge: how to achieve a high-fidelity transfer of an independently prepared quantum state of light onto the atomic quantum state? Here we propose and experimentally demonstrate a protocol for such quantum memory based on atomic ensembles. We demonstrate for the first time a recording of an externally provided quantum state of light onto the atomic quantum memory with a fidelity up to 70%, significantly higher than that for the classical recording. Quantum storage of light is achieved in three steps: an interaction of light with atoms, the subsequent measurement on the transmitted light, and the feedback onto the atoms conditioned on the measurement result. Density of recorded states 33% higher than that for the best classical recording of light on atoms is achieved. A quantum memory lifetime of up to 4 msec is demonstrated.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2004-10-11T13:54:35.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "experimental demonstration",
      "demonstrate",
      "atomic quantum state",
      "quantum memory lifetime",
      "atomic quantum memory"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 22,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}