{
  "abstract": "Composition modulation is a powerful technique for designing materials with tailored properties, fueling the development of advanced semiconductor devices. In this work, we have implemented this technique into Ge quantum well heterostructures, offering a promising avenue to address the critical challenge of charge stability in spin qubit devices. Harnessing the atomic-scale precision of molecular beam epitaxy, we have engineered the band structure of the SiGe top barrier via graded composition modulation, thereby reducing charge accumulation states at the SiGe-dielectric interface and strengthening the effective confinement to the hole gases in the Ge quantum wells. The enhanced charge stability of composition-modulated SiGe/Ge quantum well heterostructures is confirmed in Hall devices, featuring an enlarged stable gate voltage range. We have further fabricated quantum dot devices from the composition-modulated SiGe/Ge quantum well heterostructures and observed remarkably low charge noise with an averaged amplitude of $0.46\\,\\mathrm{μeV}/\\mathrm{\\sqrt{Hz}}$ at $1\\,\\mathrm{Hz}$---the lowest reported value for Ge quantum wells grown on silicon. This exceptional charge stability of the quantum dots persists in the few-hole regime, with no observable voltage drift over $\\sim$hours. With reduced charge noise and enhanced energy stability, composition-modulated SiGe/Ge heterostructures exhibit significant potential for applications in building high-performance quantum devices, including spin qubits with a long coherence time.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.11214",
  "author_total": 13,
  "authors": [
    {
      "name": "Ding-Ming Huang"
    },
    {
      "name": "Jun-Hang Liu"
    },
    {
      "name": "Han Gao"
    },
    {
      "name": "Jie-Yin Zhang"
    },
    {
      "name": "Jian-Huan Wang"
    },
    {
      "name": "Fang-Ze Liu"
    },
    {
      "name": "Xin-Yu Zhou"
    },
    {
      "name": "Yi Luo"
    },
    {
      "name": "Bin-Xiao Fu"
    },
    {
      "name": "Xiao-Fei Liu"
    },
    {
      "name": "Ji-Yin Wang"
    },
    {
      "name": "Jian-Jun Zhang"
    },
    {
      "name": "H. Q. Xu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/578x07vj5e4cq.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.11214",
  "fulltext_url": null,
  "id": "578x07vj5e4cq",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.11214",
  "language": null,
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mes-hall"
    ],
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "3107|Quantum and electron transport phenomena"
    ]
  ],
  "openalex": "W7212276340",
  "pdf_url": "https://arxiv.org/pdf/2609.11214",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-10",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/578x07vj5e4cq.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:26Z",
      "native_id": "2609.11214",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.11214"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Enhancing charge stability of Ge quantum well heterostructures via SiGe layer composition engineering",
  "title_text": "Enhancing charge stability of Ge quantum well heterostructures via SiGe layer composition engineering",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:26Z",
  "url": "https://research.draconitic.com/paper/578x07vj5e4cq",
  "venue": "arXiv",
  "versions": []
}