{
  "annotation_id": "8e47ebeb-7959-4225-8e99-afbbc983e627",
  "date_created": "2026-03-02T18:01:38.865000Z",
  "date_modified": "2026-03-02T18:01:38.865000Z",
  "file_hash": "a1e87966bea8e03b3cce4e6d6b0884198ba715a6925e7ee11adfa523dd519788",
  "private": false,
  "record": {
    "abstract": "I investigate dense coding with a general mixed state on the Hilbert space\n$C^{d}\\otimes C^{d}$ shared between a sender and receiver. The following result\nis proved. When the sender prepares the signal states by mutually orthogonal\nunitary transformations with equal {\\it a priori} probabilities, the capacity\nof dense coding is maximized. It is also proved that the optimal capacity of\ndense coding $\\chi ^{*}$ satisfies $E_{R}(\\rho)\\leq \\chi ^{*}\\leq E_{R}(\\rho\n)+\\log_{2}d$, where $E_{R}(\\rho)$ is the relative entropy of entanglement of\nthe shared entangled state.",
    "arxiv_id": "quant-ph/0009048",
    "authors": [
      "Tohya Hiroshima"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/0305-4470/34/35/316",
    "journal_ref": "J. Phys. A: Math. Gen. 34 (2001) 6907-6912",
    "title": "Optimal dense coding with mixed state entanglement",
    "url": "https://arxiv.org/abs/quant-ph/0009048"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "10a46cdd-4f43-407b-8a15-003e854e420e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}