{
  "annotation_id": "3860a3b0-d2e7-4ab8-9476-e4724f3e4f06",
  "date_created": "2026-03-02T18:02:20.629000Z",
  "date_modified": "2026-03-02T18:02:20.629000Z",
  "file_hash": "bc3dc27f3bcff53ba2d57a4cde68906834b62ab57c8669446497a41ca73c6231",
  "private": false,
  "record": {
    "abstract": "If two parties share an unknown quantum state, one can ask how much quantum\ncommunication is needed for party A to send her share to party B. Recently, it\nwas found that the number of qubits which should be sent is given by the\nconditional entropy. This quantifies the notion of partial information, and it\ncan even be negative. Here, we not only demand that A send her state to B, but\nadditionally, B should send his state to A. Paradoxically, we find that\nrequiring that the parties perform this additional task can lower the amount of\nquantum communication required. This primitive, which we call quantum state\nexchange, can be used to quantify the notion of uncommon information, since the\ntwo parties only need to send each other the parts of their state they don\u0027t\nhold in common. In the classical case, the concept of uncommon information\nfollows trivially from the concept of partial information. We find that for\nquantum states, this is not so. We prove upper and lower bounds for the\nuncommon information and find optimal protocols for several classes of states.",
    "arxiv_id": "quant-ph/0511082",
    "authors": [
      "Jonathan Oppenheim",
      "Andreas Winter"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "Uncommon information (the cost of exchanging a quantum state)",
    "url": "https://arxiv.org/abs/quant-ph/0511082"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "a66677e8-325c-4186-bc01-6ec97fb1d42b",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}