{
  "annotation_id": "c4a40b88-beec-4410-8fb8-8852b1b4b3ad",
  "date_created": "2026-03-02T18:01:59.486000Z",
  "date_modified": "2026-03-02T18:01:59.486000Z",
  "file_hash": "7c7244cd6d13178b6a5384ad25b027de9637886e5d101c69c6a1b058701ff73b",
  "private": false,
  "record": {
    "abstract": "A programmable gate array is a circuit whose action is controlled by input\ndata. In this letter we describe a special--purpose quantum circuit that can be\nprogrammed to evaluate the expectation value of any operator $O$ acting on a\nspace of states of $N$ dimensions. The circuit has a program register whose\nstate $|\\Psi(O)\u003e_P$ encodes the operator $O$ whose expectation value is to be\nevaluated. The method requires knowledge of the expansion of $O$ in a basis of\nthe space of operators. We discuss some applications of this circuit and its\nrelation to known instances of quantum state tomography.",
    "arxiv_id": "quant-ph/0306143",
    "authors": [
      "Juan Pablo Paz",
      "Augusto Roncaglia"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.68.052316",
    "title": "A quantum gate array can be programmed to evaluate the expectation value   of any operator",
    "url": "https://arxiv.org/abs/quant-ph/0306143"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "9f143af5-7068-4c64-9999-ce779a22bcc0",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}