{
  "abstract": "Deterministic spin-orbit torque (SOT) switching of perpendicular magnets without external magnetic fields remains a central challenge for scalable SOT-MRAM. Here, we demonstrate that dimensional engineering of a Co/W superlattice spin-orbit layer enables >90% field-free switching of perpendicular CoFeB. Harmonic Hall measurements reveal an unconventional out-of-plane torque, while first-principles calculations reveal reconstruction of the spin-resolved electronic structure and increased W-projected out-of-plane spin character, together supporting the modification of torque symmetry through Co/W superlattice engineering. The optimized superlattice achieves a critical current density of 23.3 MA cm-2 and a thermal stability factor Δ ≈ 45. Nanoscale devices (100 nm) preserve deterministic field-free reversal with comparable efficiency, confirming scalability toward magnetic tunnel junction integration. Micromagnetic analysis shows that out-of-plane spin-polarized torque together with canted anisotropy enables intrinsic symmetry breaking, highlighting superlattice engineering as a route to tailor torque symmetry for effective field-free SOT devices.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Materials Science & Engineering, National Yang-Ming Chiao-Tung University, Hsinchu30010, Taiwan, ROC.",
    "Department of Materials Science & Engineering, National Taiwan University, Taipei10617, Taiwan, ROC.",
    "Taiwan Semiconductor Research Institute, Hsinchu30010, Taiwan, ROC.",
    "Department of Physics, National Taiwan University, Taipei10617, Taiwan, ROC.",
    "Center of Atomic Initiatives for New Materials, National Taiwan University, Taipei10617, Taiwan, ROC.",
    "TopoLogic Inc., Tokyo113-0033, Japan."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 10,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Yu-Lon Lin"
    },
    {
      "affs": [
        0
      ],
      "name": "Jing-Wen Chen"
    },
    {
      "affs": [
        0
      ],
      "name": "Yan-Zhen Huang"
    },
    {
      "affs": [
        1
      ],
      "name": "Tzu-Chuan Hsin"
    },
    {
      "affs": [
        0
      ],
      "name": "Chih-Wei Cheng"
    },
    {
      "affs": [
        2
      ],
      "name": "Yu-Han Huang"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Ssu-Yen Huang"
    },
    {
      "affs": [
        5
      ],
      "name": "Shintaro Hara"
    },
    {
      "affs": [
        5
      ],
      "name": "Tatsuya Kishi"
    },
    {
      "affs": [
        0
      ],
      "name": "Yuan-Chieh Tseng",
      "orcid": "0000-0001-5258-6152"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/a2jejsednqbrf.bib",
  "cited_by": 0,
  "doi": "10.1021/acs.nanolett.6c04408",
  "fulltext_url": "https://europepmc.org/articles/PMC13693498",
  "id": "a2jejsednqbrf",
  "issns": [
    "1530-6984",
    "1530-6992"
  ],
  "landing_url": "https://europepmc.org/article/MED/42905086",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3107|Magnetic properties of thin films"
    ]
  ],
  "openalex": "W7221515233",
  "pdf_url": "https://europepmc.org/articles/PMC13693498?pdf=render",
  "pmcid": "PMC13693498",
  "pmid": "42905086",
  "published": "2026-10-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/a2jejsednqbrf.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:57Z",
      "native_id": "MED:42905086",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42905086"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3107|Magnetic properties of thin films",
      "subfield": "amo"
    }
  ],
  "title": "Dimensional Engineering of Co/W Superlattices Enables Out-of-Plane Spin Polarization with 90% Field-Free Switching in Perpendicular CoFeB.",
  "title_text": "Dimensional Engineering of Co/W Superlattices Enables Out-of-Plane Spin Polarization with 90% Field-Free Switching in Perpendicular CoFeB.",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:19:57Z",
  "url": "https://research.draconitic.com/paper/a2jejsednqbrf",
  "venue": "Nano letters",
  "versions": []
}