{
  "abstract": "We show that an isotropic, lossless dipolar particle, locally embedded in a homogeneous, lossless host, cannot experience axial optical torque under any illumination, in any photonic environment, whatever its own chirality--a general identity extending the sphere-in-free-space result to arbitrary chiral and substrate-coupled environments. Shape anisotropy is the essential escape route, and the resulting torque is not generic: closed-form, radiative-reaction-dressed polarizabilities for a chiral dielectric ellipsoid show its loss-free \"optical spanner\" torque changing by an order of magnitude between enantiomers (κ\\to -κ), a mechanical response impossible for any sphere. Above a high-index or lossy substrate like gold or silicon, standing-wave enhancement, or simply a larger particle at a near-contact gap, brings it beyond optical-torque-wrench thresholds.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.28696",
  "author_total": 3,
  "authors": [
    {
      "name": "Juanjuan Ren"
    },
    {
      "name": "Reuven Gordon"
    },
    {
      "name": "Stephen Hughes"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/csb8ak7fxac0m.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.28696",
  "fulltext_url": null,
  "id": "csb8ak7fxac0m",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.28696",
  "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",
      "physics.optics"
    ],
    [
      "openalex",
      "3107|Orbital Angular Momentum in Optics"
    ]
  ],
  "openalex": "W7214294682",
  "pdf_url": "https://arxiv.org/pdf/2609.28696",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/csb8ak7fxac0m.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:24:11Z",
      "native_id": "2609.28696",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.28696"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.optics",
      "subfield": "optics-photonics"
    }
  ],
  "title": "A general no-go theorem for loss-free optical torque, and its enantiomer-differential escape route",
  "title_text": "A general no-go theorem for loss-free optical torque, and its enantiomer-differential escape route",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:11Z",
  "url": "https://research.draconitic.com/paper/csb8ak7fxac0m",
  "venue": "arXiv",
  "versions": []
}