{
  "annotation_id": "35e04f55-d233-4b81-95c3-ebdce96106c6",
  "date_created": "2026-03-02T18:02:24.121000Z",
  "date_modified": "2026-03-02T18:02:24.121000Z",
  "file_hash": "0aceda9a0808b50ca148a96acda85b477d74f1291cfe1cd6afc09f93808a17a4",
  "private": false,
  "record": {
    "abstract": "Maps that are not completely positive (CP) are often useful to describe the\ndynamics of open systems. An apparent violation of complete positivity can\noccur because there are prior correlations of the principal system with the\nenvironment, or if the applied transformation is correlated with the state of\nthe system. We provide a physically motivated definition of accessible non-CP\nmaps and derive two necessary conditions for a map to be accessible. We also\nshow that entanglement between the system and the environment is not necessary\nto generate a non-CP dynamics. We describe two simple approximations that may\nbe sufficient for some problems in process tomography, and then outline what\nthese methods may be able to tell us in other situations where non-CP dynamics\nnaturally arise.",
    "arxiv_id": "quant-ph/0512167",
    "authors": [
      "Hilary Carteret",
      "Daniel R. Terno",
      "Karol Zyczkowski"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.77.042113",
    "journal_ref": "Phys. Rev A 77, 042113 (2008)",
    "title": "Physical accessibility of non-completely positive maps",
    "url": "https://arxiv.org/abs/quant-ph/0512167"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "8a6c50a0-1b9d-42ed-adca-f66740c23601",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}