{
  "annotation_id": "a4a2d805-f965-4f7f-bf42-8b57eacc820a",
  "date_created": "2026-03-02T18:01:56.058000Z",
  "date_modified": "2026-03-02T18:01:56.058000Z",
  "file_hash": "5cb243fbfb32d915875afce123ff28fa797d2f91b82f5530c3e387db4f8c7296",
  "private": false,
  "record": {
    "abstract": "A class of quantum channels and completely positive maps (CPMs) are\nintroduced and investigated. These, which we call subspace preserving (SP) CPMs\nhas, in the case of trace preserving CPMs, a simple interpretation as those\nwhich preserve probability weights on a given orthogonal sum decomposition of\nthe Hilbert space of a quantum system. Several equivalent characterizations of\nSP CPMs are proved and an explicit construction of all SP CPMs, is provided.\nFor a subclass of the SP channels a construction in terms of joint unitary\nevolution with an ancilla system, is presented.",
    "arxiv_id": "quant-ph/0302180",
    "authors": [
      "Johan \u00c5berg"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1016/j.aop.2004.04.013",
    "journal_ref": "Annals of Physics Vol. 313, p. 326 (2004)",
    "title": "Subspace preserving completely positive maps",
    "url": "https://arxiv.org/abs/quant-ph/0302180"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "6bf23716-0b67-47a1-90bc-326fd46b68e1",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}