{
  "id": "0907.2453",
  "version": "v4",
  "published": "2009-07-14T21:10:49.000Z",
  "updated": "2010-03-20T15:49:15.000Z",
  "title": "Quantum noise limited and entanglement-assisted magnetometry",
  "authors": [
    "W. Wasilewski",
    "K. Jensen",
    "H. Krauter",
    "J. J. Renema",
    "M. V. Balabas",
    "E. S. Polzik"
  ],
  "comment": "To appear in Physical Review Letters, April 9 issue (provisionally)",
  "journal": "Phys. Rev. Lett. 104, 133601 (2010); Erratum: Phys. Rev. Lett. 104, 209902(E) (2010)",
  "doi": "10.1103/PhysRevLett.104.133601",
  "categories": [
    "quant-ph"
  ],
  "abstract": "We study experimentally the fundamental limits of sensitivity of an atomic radio-frequency magnetometer. First we apply an optimal sequence of state preparation, evolution, and the back-action evading measurement to achieve a nearly projection noise limited sensitivity. We furthermore experimentally demonstrate that Einstein-Podolsky-Rosen (EPR) entanglement of atoms generated by a measurement enhances the sensitivity to pulsed magnetic fields. We demonstrate this quantum limited sensing in a magnetometer utilizing a truly macroscopic ensemble of 1.5*10^12 atoms which allows us to achieve sub-femtoTesla/sqrt(Hz) sensitivity.",
  "revisions": [
    {
      "version": "v4",
      "updated": "2010-03-20T15:49:15.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "42.50.Dv",
      "03.67.-a",
      "42.50.Gy"
    ],
    "keywords": [
      "quantum noise",
      "entanglement-assisted magnetometry",
      "atomic radio-frequency magnetometer",
      "projection noise limited sensitivity",
      "fundamental limits"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review Letters",
      "year": 2010,
      "month": "Apr",
      "volume": 104,
      "number": 13,
      "pages": 133601
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2010PhRvL.104m3601W"
    }
  }
}