{
  "abstract": "Kerr-cat qubits offer a hardware-efficient route to fault-tolerant quantum computing by suppressing bit-flip errors exponentially, while phase-flip errors increase only linearly with the mean photon number. To maintain this protection, entangling operations must be bias-preserving, ensuring that phase-flip errors occurring during the gate do not propagate into bit-flip errors. In this paper, we propose an asymmetrically threaded SQUID (ATS) parametric coupler to implement high-fidelity, bias-preserving entangling gates between Kerr-cat qubits. By engineering a photon-number asymmetry between the control and target modes, we enable fast gate operations that suppress non-adiabatic leakage without complex pulse shaping. Through numerical simulations of the full circuit Hamiltonian, we demonstrate a bias-preserving CX gate achieving 99.69% fidelity in the absence of photon loss for a gate duration of 50 ns. Under a single-photon loss rate of 100 kHz, our protocol yields a noise bias of 9922, exceeding the noise bias of a naive non-bias-preserving CX implementation by approximately a factor of 570. These results support the ATS coupler as a valuable building block for concatenated cat-qubit architectures.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.28749",
  "author_total": 6,
  "authors": [
    {
      "name": "Kerem Yurtseven"
    },
    {
      "name": "Shantanu R. Jha"
    },
    {
      "name": "Apoorva Limaye"
    },
    {
      "name": "Risav Pokhrel"
    },
    {
      "name": "Maral Mahmoudi Kamelabad"
    },
    {
      "name": "Muhammad Waqar Amin"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/37283xevkdv54.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.28749",
  "fulltext_url": null,
  "id": "37283xevkdv54",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.28749",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Information and Cryptography"
    ]
  ],
  "openalex": "W7223237093",
  "pdf_url": "https://arxiv.org/pdf/2610.28749",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/37283xevkdv54.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2610.28749",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.28749"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Bias-Preserving Entanglement of Kerr-Cat Qubits with an ATS Coupler",
  "title_text": "Bias-Preserving Entanglement of Kerr-Cat Qubits with an ATS Coupler",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/37283xevkdv54",
  "venue": "arXiv",
  "versions": []
}