{
  "annotation_id": "ea259ab2-522c-4815-b252-4ca1f487ad05",
  "date_created": "2026-03-02T18:00:49.854000Z",
  "date_modified": "2026-03-02T18:00:49.854000Z",
  "file_hash": "f43ea4d90278feac1cd232d41774cc1b3cbda44ab2dc1276dd02b3a1e3100d22",
  "private": false,
  "record": {
    "abstract": "The Bruggeman formalism is implemented to estimate the refractive index of an\nisotropic, dielectric, homogenized composite medium (HCM). Invoking the\nwell--known Hashin--Shtrikman bounds, we demonstrate that the group velocity in\ncertain HCMs can exceed the group velocities in their component materials. Such\nHCMs should therefore be considered as metamaterials.",
    "arxiv_id": "physics/0402037",
    "authors": [
      "T. G. Mackay",
      "A. Lakhtakia"
    ],
    "categories": [
      "physics.optics",
      "physics.class-ph"
    ],
    "doi": "10.1088/0305-4470/37/1/L04",
    "journal_ref": "J. Phys. A: Math. Gen., Vol. 37, pp. L19-L24, 2004",
    "title": "Enhanced group velocity in metamaterials",
    "url": "https://arxiv.org/abs/physics/0402037"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "245eacf1-0ec4-4e83-8f13-5dbaf6a879de",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}