{
  "annotation_id": "0c7169ca-579e-4599-8f61-db2587dd3615",
  "date_created": "2026-03-02T18:02:02.662000Z",
  "date_modified": "2026-03-02T18:02:02.662000Z",
  "file_hash": "8eed16443716540b22557d46defcb4c7490c3acd2fec7ae563d1173792072855",
  "private": false,
  "record": {
    "abstract": "In this paper we discuss a model of quantum computer in which a state is an\noperator of density matrix and gates are general quantum operations, not\nnecessarily unitary. A mixed state (operator of density matrix) of n two-level\nquantum systems is considered as an element of 4^n-dimensional operator Hilbert\nspace (Liouville space). It allows to use a quantum computer model with\nfour-valued logic. The gates of this model are general superoperators which act\non n-ququat state. Ququat is a quantum state in a four-dimensional (operator)\nHilbert space. Unitary two-valued logic gates and quantum operations for an\nn-qubit open system are considered as four-valued logic gates acting on\nn-ququat. We discuss properties of quantum four-valued logic gates. In the\npaper we study universality for quantum four-valued logic gates.",
    "arxiv_id": "quant-ph/0312131",
    "authors": [
      "Vasily E. Tarasov"
    ],
    "categories": [
      "quant-ph",
      "cond-mat.soft",
      "hep-th"
    ],
    "doi": "10.1088/0305-4470/35/25/305",
    "journal_ref": "Journal of Physics A. Vol.35. No.25. (2002) 5207-5236",
    "title": "Quantum Computer with Mixed States and Four-Valued Logic",
    "url": "https://arxiv.org/abs/quant-ph/0312131"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "8d3b6994-98b5-45d0-bf0d-d4dcc65185b3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}