{
  "id": "quant-ph/0201040",
  "version": "v1",
  "published": "2002-01-10T19:54:12.000Z",
  "updated": "2002-01-10T19:54:12.000Z",
  "title": "Classical states and decoherence by unitary evolution in the thermodynamic limit",
  "authors": [
    "Marco Frasca"
  ],
  "comment": "7 pages, no figures. Contribution to the proceedings of the IV edition of the Garda Lake Workshop \"Mysteries, Puzzles and Paradoxes in Quantum Mechanics\", August 27 - September 1, 2001",
  "journal": "J.Opt.B Quant.Semiclass.Opt.4:S443-S445,2002",
  "doi": "10.1088/1464-4266/4/4/336",
  "categories": [
    "quant-ph",
    "cond-mat.str-el",
    "hep-th",
    "physics.atom-ph"
  ],
  "abstract": "It is shown how classical states, meant as states representing a classical object, can be produced in the thermodynamic limit, retaining the unitary evolution of quantum mechanics. Besides, using a simple model of a single spin interacting with a spin-bath, it is seen how decoherence, with the off-diagonal terms in the density matrix going to zero, can be obtained when the number of the spins in the bath is taken to go formally to infinity. In this case, indeed, the system appears to flop at a frequency being formally infinity that, from a physical standpoint, can be proved equivalent to a time average.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2002-01-10T19:54:12.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "unitary evolution",
      "thermodynamic limit",
      "classical states",
      "decoherence",
      "simple model"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "Journal of Optics B: Quantum and Semiclassical Optics",
      "year": 2002,
      "month": "Aug",
      "volume": 4
    },
    "note": {
      "typesetting": "TeX",
      "pages": 7,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 581673,
      "adsabs": "2002JOptB...4S.443F"
    }
  }
}