{
  "annotation_id": "611ad673-b620-460a-897c-db56ef18d658",
  "date_created": "2026-03-02T18:02:05.749000Z",
  "date_modified": "2026-03-02T18:02:05.749000Z",
  "file_hash": "32fd6991c364ad2bbc5c41edc80fd48e3de9b66d110bd58440a70c9e42fd0752",
  "private": false,
  "record": {
    "abstract": "A positive P-representation for the spin-j thermal density matrix is given in\nclosed form. The representation is constructed by regarding the wave function\nas the internal state of a closed-loop control system. A continuous\ninterferometric measurement process is proved to einselect coherent states, and\nfeedback control is proved to be equivalent to a thermal reservoir. Ito\nequations are derived, and the P-representation is obtained from a\nFokker-Planck equation. Langevin equations are derived, and the force noise is\nshown to be the Hilbert transform of the measurement noise. The formalism is\napplied to magnetic resonance force microscopy (MRFM) and gravity wave (GW)\ninterferometry. Some unsolved problems relating to drift and diffusion on\nHilbert spaces are noted.",
    "arxiv_id": "quant-ph/0401165",
    "authors": [
      "John A. Sidles"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "Positive P-Representations of the Thermal Operator from Quantum Control   Theory",
    "url": "https://arxiv.org/abs/quant-ph/0401165"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "409ee957-6938-4547-9a60-8da78bd9398f",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}