{
  "annotation_id": "645306e7-8e55-44ea-b374-eb04d207d5de",
  "date_created": "2026-03-02T18:02:37.074000Z",
  "date_modified": "2026-03-02T18:02:37.074000Z",
  "file_hash": "bb8a72375dfdec237ed6e0fc8d050eceb5521256cb5c3acad9c10b5e305c3da7",
  "private": false,
  "record": {
    "abstract": "A new operator based condition for distinguishing classical from\nnon-classical states of quantised radiation is developed. It exploits the fact\nthat the normal ordering rule of correspondence to go from classical to quantum\ndynamical variables does not in general maintain positivity. It is shown that\nthe approach naturally leads to distinguishing several layers of increasing\nnonclassicality, with more layers as the number of modes increases. A\ngeneralisation of the notion of subpoissonian statistics for two-mode radiation\nfields is achieved by analysing completely all correlations and fluctuations in\nquadratic combinations of mode annihilation and creation operators conserving\nthe total photon number. This generalisation is nontrivial and intrinsically\ntwo-mode as it goes beyond all possible single mode projections of the two-mode\nfield. The nonclassicality of pair coherent states, squeezed vacuum and\nsqueezed thermal states is analysed and contrasted with one another, comparing\nthe generalised subpoissonian statistics with extant signatures of nonclassical\nbehaviour.",
    "arxiv_id": "quant-ph/9512020",
    "authors": [
      "Arvind",
      "N. Mukunda",
      "R. Simon"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/0305-4470/31/2/016",
    "journal_ref": "J.Phys.A31:565-583,1998",
    "title": "Characterisations of Classical and Non-classical states of Quantised   Radiation",
    "url": "https://arxiv.org/abs/quant-ph/9512020"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "e59df5ce-a01d-4daf-85f4-517e437f2c38",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}