{
  "annotation_id": "9152ec48-3a20-4345-a493-76f1f8af194e",
  "date_created": "2026-03-02T18:01:51.833000Z",
  "date_modified": "2026-03-02T18:01:51.833000Z",
  "file_hash": "f6def4106711e2ccfaeef8d323dca29fd08681888dc8cc41f39d5963d3fba23d",
  "private": false,
  "record": {
    "abstract": "We investigate the capacity of three symmetric quantum states in three real\ndimensions to carry classical information. Several such capacities have already\nbeen defined, depending on what operations are allowed in the sending and\nreceiving protocols. These include the C_{1,1} capacity, which is the capacity\nachievable if separate measurements must be used for each of the received\nstates, and the C_{1,infinity} capacity, which is the capacity achievable if\njoint measurements are allowed on the tensor product of all the received\nstates. We discover a new classical information capacity of quantum channels,\nthe adaptive capacity C_{1,A}, which lies strictly between the C_{1,1} and the\nC_{1,infinity} capacities. The adaptive capacity requires each of the signals\nto be measured by a separate apparatus, but allows the quantum states of these\nsignals to be measured in stages, with the first stage partially reducing their\nquantum states, and where measurements in subsequent stages which further\nreduce the quantum states may depend on the results of a classical computation\ntaking as input the outcomes of the first round of measurements.",
    "arxiv_id": "quant-ph/0206058",
    "authors": [
      "Peter W. Shor"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "The Adaptive Classical Capacity of a Quantum Channel, or Information   Capacities of Three Symmetric Pure States in Three Dimensions",
    "url": "https://arxiv.org/abs/quant-ph/0206058"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "e374b08a-0e91-42eb-b601-bf44a9f40f0d",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}