{
  "annotation_id": "12d12f60-5c86-42b3-9e72-fb5293f650f0",
  "date_created": "2026-03-02T18:02:13.035000Z",
  "date_modified": "2026-03-02T18:02:13.035000Z",
  "file_hash": "6b51c2fc4d0c57f69145947e09786afc90547b26b1d0b2b569536e3294d452f2",
  "private": false,
  "record": {
    "abstract": "It is experimentally demonstrated that an arbitrary quantum state of a single\nspin 1/2: a|u\u003e + b|d\u003e can be converted into a superposition of the two\nferromagnetic states of a spin cluster: a|uu...uu\u003e + b|dd...dd\u003e. The physical\nsystem is a cluster of seven dipolar-coupled nuclear spins of single-labeled\n13C-benzene molecules in a liquid-crystalline matrix. In this complex system,\nthe pseudopure ground state and the required controlled unitary transformations\nhave been implemented. The experimental scheme can be considered as an explicit\nmodel of quantum measurement.",
    "arxiv_id": "quant-ph/0501123",
    "authors": [
      "Jae-Seung Lee",
      "A. K. Khitrin"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevLett.94.150504",
    "journal_ref": "Physical Review Letters 94, 150504 (2005)",
    "title": "Quantum state expansion",
    "url": "https://arxiv.org/abs/quant-ph/0501123"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "a766bc07-9abd-4a65-9034-09fd21cd7443",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}