{
  "annotation_id": "c70db0c0-8727-432e-a706-aeff37dabe9c",
  "date_created": "2026-03-02T18:01:17.243000Z",
  "date_modified": "2026-03-02T18:01:17.243000Z",
  "file_hash": "c15e1681f23ec69ba885246ddd055034f4eca7d7f113c5402af46decd02a2ac5",
  "private": false,
  "record": {
    "abstract": "A metamaterial with a negative effective index of refraction is made from a\nthree-dimensional hexagonal lattice photonic crystal with a metallic basis\nembedded in foam. It has been simulated with Ansoft HFSSTM in a frequency range\nfrom 7.0 to 12.0 GHz. Simulated results tested experimentally and negative\nrefraction verified in some frequencies. Experimental results are in excellent\nagreement with simulations.",
    "arxiv_id": "physics/0701260",
    "authors": [
      "Ali Mahmoudi",
      "Abbas Semnani",
      "Ramazan Alizadeh",
      "Roohollah Adeli"
    ],
    "categories": [
      "physics.optics"
    ],
    "doi": "10.1051/epjap:2007099",
    "journal_ref": "Eur. Phys. J. Appl. Phys. (2007)",
    "title": "Negative refraction of a three-dimensional metallic photonic crystal",
    "url": "https://arxiv.org/abs/physics/0701260"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "9de44fbe-7b57-43b9-b5b6-bbf929d21567",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}