{
  "annotation_id": "05d42f8d-7356-457c-bf37-919e01728368",
  "date_created": "2026-03-02T18:01:48.885000Z",
  "date_modified": "2026-03-02T18:01:48.885000Z",
  "file_hash": "3d34009797ecda71f411d59b79747cd71cb4ccc67813fa34c8dba9bab5882cb6",
  "private": false,
  "record": {
    "abstract": "We study a simplified Heisenberg spin model in order to clarify the idea of\ndecoherence in closed quantum systems. For this purpose, we define a new\nconcept: the decoherence function \\Xi(t), which describes the dynamics of\ndecoherence in the whole system, and which is linked with the total (von\nNeumann) entropy of all particles. As expected, decoherence is understood both\nas a statistical process that is caused by the dynamics of the system, and also\nas a matter of entropy. Moreover, the concept of decoherence time is applicable\nin closed systems and we have solved its behaviour in the Heisenberg model with\nrespect to particle number N, density \\rho and spatial dimension D in a 1/r\n-type of potential. We have also studied the Poincare recurrences occurring in\nthese types of systems: in an N=1000 particle system the recurrence time is\nclose to the order of the age of the universe. This encourages us to conclude\nthat decoherence is the solution for quantum-classical problems not only in\npractice, but also in principle.",
    "arxiv_id": "quant-ph/0202169",
    "authors": [
      "Olavi Dannenberg"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "Decoherence in the Heisenberg model",
    "url": "https://arxiv.org/abs/quant-ph/0202169"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "74e58221-1566-43b8-b253-f2421b594f40",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}