{
  "annotation_id": "6044b15a-1962-4c76-b322-40e6d0d4adaf",
  "date_created": "2026-03-02T18:01:49.512000Z",
  "date_modified": "2026-03-02T18:01:49.512000Z",
  "file_hash": "87839e30af2e3b32da12bc44dac681c064934678a9160f126809c8c434a8aa29",
  "private": false,
  "record": {
    "abstract": "It is shown how classical states, meant as states representing a classical\nobject, can be produced in the thermodynamic limit, retaining the unitary\nevolution of quantum mechanics. Besides, using a simple model of a single spin\ninteracting with a spin-bath, it is seen how decoherence, with the off-diagonal\nterms in the density matrix going to zero, can be obtained when the number of\nthe spins in the bath is taken to go formally to infinity. In this case,\nindeed, the system appears to flop at a frequency being formally infinity that,\nfrom a physical standpoint, can be proved equivalent to a time average.",
    "arxiv_id": "quant-ph/0201040",
    "authors": [
      "Marco Frasca"
    ],
    "categories": [
      "quant-ph",
      "cond-mat.str-el",
      "hep-th",
      "physics.atom-ph"
    ],
    "doi": "10.1088/1464-4266/4/4/336",
    "journal_ref": "J.Opt.B Quant.Semiclass.Opt.4:S443-S445,2002",
    "title": "Classical states and decoherence by unitary evolution in the   thermodynamic limit",
    "url": "https://arxiv.org/abs/quant-ph/0201040"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "8adf1db9-a1f6-4589-88ce-cf670b3c288b",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}