{
  "annotation_id": "7f968140-d884-4270-9740-3f12ff609c8a",
  "date_created": "2026-03-02T18:01:48.280000Z",
  "date_modified": "2026-03-02T18:01:48.280000Z",
  "file_hash": "c2e9b96c769c23c017bbd4cf53fe56912930b511088a662b9e3cc5808ac6a199",
  "private": false,
  "record": {
    "abstract": "We investigate properties of the structural physical approximation (SPA) of\nthe partial transposition map recently introduced by Horodecki and Ekert\n[quant-ph/0111064]. We focus on the case of two-qubit states and show that in\nthis case the map has the structure of a generalized quantum measurement\nfollowed by preparation of a suitable output state. We also introduce SPA for\nmap that transforms two copies of density matrix of a single qubit onto a\nsquare of that matrix. We prove that also this map is essentially a generalized\nquantum measurement.",
    "arxiv_id": "quant-ph/0111107",
    "authors": [
      "Jaromir Fiurasek"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.66.052315",
    "journal_ref": "Phys. Rev. A 66, 052315 (2002).",
    "title": "Structural physical approximations of unphysical maps and generalized   quantum measurements",
    "url": "https://arxiv.org/abs/quant-ph/0111107"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "277e6888-a656-424d-96c0-97c5a8b2a654",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}