{
  "abstract": "For a free scalar particle in one spatial dimension, in a single-pass half-line geometry, we compare the absorbing Robin boundary condition with the generalized Marchewka--Schuss (MS) unidirectional-current family. Robin absorption is characterized by a single parameter $κ>0$: once $κ$ is specified, its momentum-dependent absorption profile is fixed. In the generalized MS construction, by contrast, the detector response is described by a spectral function $λ(k)$, subject to the positivity and subnormalization conditions of the detection law. We show that every Robin choice of $κ$ corresponds to the particular MS calibration $λ_κ(k)=πκ/(k+κ)^2$, which reproduces the complete Robin absorption current for every admissible one-sided spectral amplitude and at every time. Thus the entire one-parameter Robin absorption family is contained within the generalized MS family. The MS construction is more general: the choice $λ_{\\rm full}(k)=π/(4k)$ gives unit absorption efficiency for every wave number, which cannot be achieved by any fixed Robin parameter. In this precise sense, the generalized MS detector process extends the Robin absorbing-boundary family. We also compare their asymptotic behavior in the ballistic fixed-ray regime and in the fixed-distance late-time limit.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.29969",
  "author_total": 1,
  "authors": [
    {
      "name": "Avi Marchewka"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8pezg04ksk07a.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.29969",
  "fulltext_url": null,
  "id": "8pezg04ksk07a",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.29969",
  "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",
      "quant-ph"
    ],
    [
      "openalex",
      "2610|Spectral Theory in Mathematical Physics"
    ]
  ],
  "openalex": "W7204959873",
  "pdf_url": "https://arxiv.org/pdf/2608.29969",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8pezg04ksk07a.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:41Z",
      "native_id": "2608.29969",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.29969"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "The MS Unidirectional Current as a Generalization of the ABC Absorption Current",
  "title_text": "The MS Unidirectional Current as a Generalization of the ABC Absorption Current",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:41Z",
  "url": "https://research.draconitic.com/paper/8pezg04ksk07a",
  "venue": "arXiv",
  "versions": []
}