{
  "id": "quant-ph/0306019",
  "version": "v1",
  "published": "2003-06-03T07:49:13.000Z",
  "updated": "2003-06-03T07:49:13.000Z",
  "title": "Decoherence without dissipation?",
  "authors": [
    "Dominique Gobert",
    "Jan von Delft",
    "Vinay Ambegaokar"
  ],
  "comment": "8 pages, 4 figures",
  "doi": "10.1103/PhysRevA.70.026101",
  "categories": [
    "quant-ph"
  ],
  "abstract": "In a recent article, Ford, Lewis and O'Connell (PRA 64, 032101 (2001)) discuss a thought experiment in which a Brownian particle is subjected to a double-slit measurement. Analyzing the decay of the emerging interference pattern, they derive a decoherence rate that is much faster than previous results and even persists in the limit of vanishing dissipation. This result is based on the definition of a certain attenuation factor, which they analyze for short times. In this note, we point out that this attenuation factor captures the physics of decoherence only for times larger than a certain time t_mix, which is the time it takes until the two emerging wave packets begin to overlap. Therefore, the strategy of Ford et al of extracting the decoherence time from the regime t < t_mix is in our opinion not meaningful. If one analyzes the attenuation factor for t > t_mix, one recovers familiar behaviour for the decoherence time; in particular, no decoherence is seen in the absence of dissipation. The latter conclusion is confirmed with a simple calculation of the off-diagonal elements of the reduced density matrix.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2003-06-03T07:49:13.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dissipation",
      "decoherence time",
      "attenuation factor captures",
      "emerging wave packets begin",
      "times larger"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Phys. Rev. A"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 8,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}