{
  "annotation_id": "dae8aa76-1589-4578-a245-554effcb6c77",
  "date_created": "2026-03-02T18:02:23.964000Z",
  "date_modified": "2026-03-02T18:02:23.964000Z",
  "file_hash": "570c6bf6d9cf0a2ff475f0e16d99cd10e16227001572ce7bbcc070575fc55270",
  "private": false,
  "record": {
    "abstract": "Let $\\Phi$ be a trace-preserving, positivity-preserving (but not necessarily\ncompletely positive) linear map on the algebra of complex $2 \\times 2$\nmatrices, and let $\\Omega$ be any finite-dimensional completely positive map.\nFor $p=2$ and $p \\geq 4$, we prove that the maximal $p$-norm of the product map\n$\\Phi \\ot \\Omega$ is the product of the maximal $p$-norms of $\\Phi$ and\n$\\Omega$. Restricting $\\Phi$ to the class of completely positive maps, this\nsettles the multiplicativity question for all qubit channels in the range of\nvalues $p \\geq 4$.",
    "arxiv_id": "quant-ph/0512185",
    "authors": [
      "Christopher King",
      "Nilufer Koldan"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1063/1.2191787",
    "title": "New multiplicativity results for qubit maps",
    "url": "https://arxiv.org/abs/quant-ph/0512185"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "8cae2d8f-74de-4fb1-9631-1df8075782eb",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}