{
  "abstract": "Fast electrical spin rotations in quantum dots require strong spin-charge hybridization, but the same hybridization can increase sensitivity to detuning noise. In a double-quantum-dot (DQD) flopping-mode qubit, the sweet-spot width and the Rabi enhancement are both tied to the same orbital splitting, limiting post-fabrication optimization of the speed-coherence trade-off. Here, we demonstrate a GaAs triple-quantum-dot (TQD) flopping-mode qubit in which the detuning of the third dot, ϵ ₃₄ , provides an additional electrical tuning parameter for orbital-band flattening. Tuning ϵ ₃₄ flattens the qubit-frequency dependence on the detuning of the target DQD while maintaining strong spin-charge hybridization, enabling electrically driven Rabi frequencies above 100 MHz. We then use feedforward-neural-network (FNN) feedback to track slow qubit-frequency drift and connect this engineered operating point to high-fidelity gates. This feedback suppresses slow qubit-frequency fluctuations, reducing their standard deviation to 388 kHz, and yields a π /2 gate fidelity of 99.56% with a 4.05 ns gate time. These results identify TQD orbital-band engineering as an electrical route for tuning the speed-coherence trade-off, complementary to material-intrinsic spin-orbit coupling and fixed micromagnet geometry.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "name": "Y. Matsumoto"
    },
    {
      "name": "X.-F. Liu"
    },
    {
      "name": "A. Ludwig",
      "orcid": "0000-0002-2871-7789"
    },
    {
      "name": "A. D. Wieck"
    },
    {
      "name": "K. Koike"
    },
    {
      "name": "T. Miyoshi"
    },
    {
      "name": "T. Fujita"
    },
    {
      "name": "A. Oiwa"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1wx10qk9fgang.bib",
  "cited_by": 0,
  "doi": "10.1038/s41534-026-01400-1",
  "fulltext_url": null,
  "id": "1wx10qk9fgang",
  "issns": [
    "2056-6387"
  ],
  "landing_url": "https://www.nature.com/articles/s41534-026-01400-1",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3107|Quantum and electron transport phenomena"
    ]
  ],
  "openalex": "W7223460094",
  "pdf_url": "https://www.nature.com/articles/s41534-026-01400-1_reference.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-24",
  "publisher": "Springer Science and Business Media LLC",
  "ris": "https://research.draconitic.com/paper/1wx10qk9fgang.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:08Z",
      "native_id": "10.1038/s41534-026-01400-1",
      "source": "crossref",
      "url": "https://www.nature.com/articles/s41534-026-01400-1"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Quantum and electron transport phenomena",
      "subfield": "amo"
    }
  ],
  "title": "High-fidelity flopping-mode single-spin operation via triple-dot orbital-band engineering",
  "title_text": "High-fidelity flopping-mode single-spin operation via triple-dot orbital-band engineering",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:08Z",
  "url": "https://research.draconitic.com/paper/1wx10qk9fgang",
  "venue": "npj Quantum Information",
  "versions": []
}