{
  "annotation_id": "1164038d-8bf9-4b2c-98ae-14c0767e9895",
  "date_created": "2026-03-02T18:02:16.022000Z",
  "date_modified": "2026-03-02T18:02:16.022000Z",
  "file_hash": "71ef2a66cecca1662e39fd01ebcc0c24d956af6518efe72a76c7a2e24dc843eb",
  "private": false,
  "record": {
    "abstract": "We consider generalizations of depolarizing channels to maps in which the\nidentity channel is replaced by a convex combinations of unitary conjugations.\n  We show that one can construct unital channels of this type for which the\ninput which achieves maximal output purity is unique. We give conditions under\nwhich multiplicativity of the maximal p-norm and additivity of the minimal\noutput entropy. We also show that the Holevo capacity need not equal log d -\nthe minimal entropy as one might expect for a convex combination of unitary\nconjugations. Conversely, we give examples for which this condition holds, but\nthe channel has no evident covariance properties.",
    "arxiv_id": "quant-ph/0505048",
    "authors": [
      "Nilanjana Datta",
      "Mary Beth Ruskai"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/0305-4470/38/45/005",
    "journal_ref": "J. Phys. A: Math. Gen. 3, 9785-9802 (2005)",
    "title": "Maximal output purity and capacity for asymmetric unital qudit channels",
    "url": "https://arxiv.org/abs/quant-ph/0505048"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "2efbb292-7cd6-4f26-b183-28c264ba989d",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}