{
  "annotation_id": "8a117f4b-641d-43cc-9d67-02457b64cae4",
  "date_created": "2026-03-02T18:01:42.687000Z",
  "date_modified": "2026-03-02T18:01:42.687000Z",
  "file_hash": "096cf679468d03cbc74199bbf1d075de9a0f9fedefbc76a0e36247db9cd7cd09",
  "private": false,
  "record": {
    "abstract": "The notion of a qubit is ubiquitous in quantum information processing. In\nspite of the simple abstract definition of qubits as two-state quantum systems,\nidentifying qubits in physical systems is often unexpectedly difficult. There\nare an astonishing variety of ways in which qubits can emerge from devices.\nWhat essential features are required for an implementation to properly\ninstantiate a qubit? We give three typical examples and propose an operational\ncharacterization of qubits based on quantum observables and subsystems.",
    "arxiv_id": "quant-ph/0101090",
    "authors": [
      "Lorenza Viola",
      "Emanuel Knill",
      "Raymond Laflamme"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/0305-4470/34/35/331",
    "title": "Constructing Qubits in Physical Systems",
    "url": "https://arxiv.org/abs/quant-ph/0101090"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "fd3cfa4f-daa4-4a3e-9604-c61a3abe7302",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}