{
  "annotation_id": "7b233b85-2c87-4972-a36c-0f88e92c724b",
  "date_created": "2026-03-02T18:01:18.508000Z",
  "date_modified": "2026-03-02T18:01:18.508000Z",
  "file_hash": "9b42614b5a2050afe305e65bf29c0219da402ef0d5ec13fdd30033614e117879",
  "private": false,
  "record": {
    "abstract": "Ferrite materials provide magnetic shielding performance similar to commonly\nused high permeability metals but have lower intrinsic magnetic noise generated\nby thermal Johnson currents due to their high electrical resistivity.\nMeasurements inside a ferrite shield with a spin-exchange relaxation-free\natomic magnetometer reveal a noise level of 0.75 fT Hz^(-1/2), 25 times lower\nthan what would be expected in a comparable mu-metal shield. The authors\nidentify a 1/f component of the magnetic noise due to magnetization\nfluctuations and derive general relationships for the Johnson current noise and\nmagnetization noise in cylindrical ferromagnetic shields in terms of their\nconductivity and complex magnetic permeability.",
    "arxiv_id": "physics/0703115",
    "authors": [
      "T. W. Kornack",
      "S. J. Smullin",
      "S. -K. Lee",
      "M. V. Romalis"
    ],
    "categories": [
      "physics.atom-ph",
      "physics.ins-det"
    ],
    "doi": "10.1063/1.2737357",
    "journal_ref": "Appl. Phys. Lett. 90, 223501 (2007)",
    "title": "A low-noise ferrite magnetic shield",
    "url": "https://arxiv.org/abs/physics/0703115"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "4fe8de2c-a7ad-44d1-a709-f85489827917",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}