{
  "annotation_id": "9332c298-3bac-4255-907b-9cff43ce0dfe",
  "date_created": "2026-03-02T18:01:49Z",
  "date_modified": "2026-03-02T18:01:49Z",
  "file_hash": "26089ac160888ab8189f73398beb5708df070fe37b0541fa3490f3ce64cba737",
  "private": false,
  "record": {
    "abstract": "We present a simple device based on the controlled-SWAP gate that performs\nquantum state tomography. It can also be used to determine maximum and minimum\neigenvalues, expectation values of arbitrary observables, purity estimation as\nwell as characterizing quantum channels. The advantage of this scheme is that\nthe architecture is fixed and the task performed is determined by the input\ndata.",
    "arxiv_id": "quant-ph/0112073",
    "authors": [
      "Artur K. Ekert",
      "Carolina Moura Alves",
      "Daniel K. L. Oi",
      "Michal Horodecki",
      "Pawel Horodecki",
      "L. C. Kwek"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevLett.88.217901",
    "title": "Universal Quantum Estimator",
    "url": "https://arxiv.org/abs/quant-ph/0112073"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "9c2161eb-a967-4ffd-8bfd-9dba778d8e75",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}