{
  "abstract": "Scalable quantum processors require repeated qubit initialization throughout large arrays. In semiconductor spin qubits, fast initialization commonly relies on local reservoir access or measurement-based feedback, requiring dedicated infrastructure that becomes increasingly difficult to distribute as processors scale. Here, we demonstrate reservoir- and measurement-free initialization of a silicon spin-qubit pair in an industrially fabricated Si/SiGe quantum-dot device using a fixed sequence of microwave and baseband pulses. Odd spin-parity states relax to the singlet charge state, whereas blocked even spin-parity states are microwave-driven through the triplet manifold and subsequently converted to the singlet by singlet-triplet mixing and charge hybridization. Repeated cycles produce the singlet-associated charge outcome with a median probability of 99.4% across the sampled preparation states, while exchange spectroscopy independently verifies mapping to the target $|\\uparrow\\downarrow\\rangle$ operational state. Microwave spectroscopy and time-domain measurements identify the dark-state-limited single-cycle transfer and the subsequent blockade-lifting dynamics that set the initialization time scale. The demonstrated pumping sequence uses approximately $12\\,μ\\mathrm{s}$ of microwave bursts and mixing dwells, while we project sub-microsecond initialization under improved device conditions. These results establish fixed-sequence microwave initialization as a scalable control primitive for semiconductor spin-qubit processors, based on singlet-triplet physics that can be adapted to platforms with suitable Pauli-blockade transitions.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.39415",
  "author_total": 7,
  "authors": [
    {
      "name": "Leon C. Camenzind"
    },
    {
      "name": "Ik Kyeong Jin"
    },
    {
      "name": "Akito Noiri"
    },
    {
      "name": "Kenta Takeda"
    },
    {
      "name": "Takashi Nakajima"
    },
    {
      "name": "Takashi Kobayashi"
    },
    {
      "name": "Seigo Tarucha"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4pjf1vtdztp1r.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.39415",
  "fulltext_url": null,
  "id": "4pjf1vtdztp1r",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.39415",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mes-hall"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "3107|Quantum and electron transport phenomena"
    ]
  ],
  "openalex": "W7215129140",
  "pdf_url": "https://arxiv.org/pdf/2609.39415",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4pjf1vtdztp1r.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:49Z",
      "native_id": "2609.39415",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.39415"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Reservoir- and Measurement-free Microwave Initialization of Semiconductor Spin Qubits",
  "title_text": "Reservoir- and Measurement-free Microwave Initialization of Semiconductor Spin Qubits",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:49Z",
  "url": "https://research.draconitic.com/paper/4pjf1vtdztp1r",
  "venue": "arXiv",
  "versions": []
}