{
  "annotation_id": "ef19c06c-6f2d-4d9b-96dd-37411e713532",
  "date_created": "2026-03-02T18:02:41.168000Z",
  "date_modified": "2026-03-02T18:02:41.168000Z",
  "file_hash": "2e4e36f6dcb39c66226bf723c2cc7ab819b7f10b01a6a9858363ff1117746ee6",
  "private": false,
  "record": {
    "abstract": "When classical information is sent through a quantum channel of nonorthogonal\nstates, there is a possibility that transmittable classical information exceeds\na channel capacity in a single use of the initial channel by extending it into\nmulti-product channel. In this paper, it is shown that this remarkable feature\nof a quantum channel, so-called superadditivity, appears even in as low as the\nthird extended coding of the simplest binary input channel. A physical\nimplementation of this channel is indicated based on cavity QED techniques.",
    "arxiv_id": "quant-ph/9705043",
    "authors": [
      "Masahide Sasaki",
      "Kentaro Kato",
      "Masayuki Izutsu",
      "Osamu Hirota"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1016/S0375-9601(97)00740-8",
    "journal_ref": "Phys.Lett. A236 (1997) 1",
    "title": "A simple quantum channel having superadditivity of channel capacity",
    "url": "https://arxiv.org/abs/quant-ph/9705043"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "0217a300-2996-4ae6-9bb6-1d4979fafea3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}