{
  "abstract": "We investigate transmission-mode second-order spatial differentiation in a stack of three twisted black-arsenic (b-As) conducting sheets separated by dielectric spacers. The symmetric twist provides a structural degree of freedom for controlling the normal-incidence Jones response and suppressing the zeroth-order helicity-converted background. Near the matching condition, the opposite-helicity transmission is dominated by a quadratic momentum-space response proportional to (kx±iky)2, giving conjugate phase windings with topological charges ℓ = ±2. The corresponding complex operator combines Cartesian and mixed second-order derivatives and produces second-order beam shaping and two-dimensional edge enhancement. Full transfer-matrix calculations confirm the expected real-space operation for both Gaussian and image inputs within the demonstrated numerical aperture. These results show how crystallographic twist and multilayer interference can be used to engineer polarization-selective spatial operators in anisotropic two-dimensional multilayers without subwavelength patterning.",
  "abstract_shown": true,
  "affiliations": [
    "School of Physics and Chemistry, Hunan First Normal University, Changsha 410205, China",
    "Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of the Ministry of Education, Hunan Normal University, Changsha 410081, China"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Wenhao Xu",
      "orcid": "0000-0001-9250-7607"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Shiyang Zhang",
      "orcid": "0000-0003-2365-9169"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Lan Xu",
      "orcid": "0000-0002-6542-0036"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1pg5htmk4br3t.bib",
  "cited_by": 0,
  "doi": "10.3390/nano16201315",
  "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13708695/?tool=EBI",
  "id": "1pg5htmk4br3t",
  "issns": [
    "2079-4991"
  ],
  "landing_url": "https://www.mdpi.com/2079-4991/16/20/1315",
  "language": "eng",
  "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",
      "2504|Metamaterials and Metasurfaces Applications"
    ]
  ],
  "openalex": "W7222943392",
  "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13708695/pdf/?tool=EBI",
  "pmcid": "PMC13708695",
  "pmid": null,
  "published": "2026-10-01",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/1pg5htmk4br3t.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:45Z",
      "native_id": "10.3390/nano16201315",
      "source": "crossref",
      "url": "https://www.mdpi.com/2079-4991/16/20/1315"
    },
    {
      "first_seen": "2026-10-30T12:21:44Z",
      "native_id": "PMC:PMC13708695",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13708695"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2504|Metamaterials and Metasurfaces Applications",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Twist-Controlled Second-Order Spatial Differentiation in a Three-Sheet Black Arsenic Stack",
  "title_text": "Twist-Controlled Second-Order Spatial Differentiation in a Three-Sheet Black Arsenic Stack",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:21:44Z",
  "url": "https://research.draconitic.com/paper/1pg5htmk4br3t",
  "venue": "Nanomaterials",
  "versions": []
}