{
  "annotation_id": "c2197c1c-bf62-4aa0-8b0c-b3c1072d9b1e",
  "date_created": "2026-03-02T18:02:24.134000Z",
  "date_modified": "2026-03-02T18:02:24.134000Z",
  "file_hash": "bcb29524d340edc36969f1d3127aae5d0ab57f36cdee60a229038c3f507f75b1",
  "private": false,
  "record": {
    "abstract": "The novel experimental realization of four-level optical quantum systems\n(ququarts) is presented. We exploit the polarization properties of frequency\nnon-degenerate biphoton field to obtain such systems. A simple method that does\nnot rely on interferometer is used to generate and measure the sequence of\nstates that can be used in quantum key distribution (QKD) protocol.",
    "arxiv_id": "quant-ph/0601091",
    "authors": [
      "E. V. Moreva",
      "G. A. Maslennikov",
      "S. S. Straupe",
      "S. P. Kulik"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "Realization of four-state qudits using biphotons",
    "url": "https://arxiv.org/abs/quant-ph/0601091"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "e1cde476-7e91-4281-941c-1a02d4cdfb26",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}