{
  "abstract": "We investigate spinon--spinon interactions in the quasi-one-dimensional $S=1/2$ Heisenberg antiferromagnet Cu(C$_4$H$_4$N$_2$)(NO$_3$)$_2$ (CuPzN) using inelastic neutron scattering. At zero field, the spectrum exhibits the canonical multi-spinon continuum of the Heisenberg chain. With increasing field we demonstrate the appearance of an energy gap $2Δ$ towards momentum $q\\rightarrow 0$ between the uniform magnetization precession mode and the shifted spinon continuum. $2Δ$ is a direct measure of spinon backscattering interactions. Comparison with numerical matrix-product-state calculations and a recent analytical theory shows excellent agreement. By examining the integrable spin-1/2 chain, we provide an example of how quasiparticle interactions can be quantified experimentally in isotropic quantum spin systems.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.34536",
  "author_total": 10,
  "authors": [
    {
      "name": "Leshan Zhao"
    },
    {
      "name": "Timothy Reeder"
    },
    {
      "name": "Matthew Stone"
    },
    {
      "name": "Daniel G. Mazzone"
    },
    {
      "name": "Jakob Lass"
    },
    {
      "name": "Christof Niedermayer"
    },
    {
      "name": "Daniel H. Reich"
    },
    {
      "name": "Anna Keselman"
    },
    {
      "name": "Oleg A. Starykh"
    },
    {
      "name": "Collin Broholm"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6b7je6zddv9m4.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.34536",
  "fulltext_url": null,
  "id": "6b7je6zddv9m4",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.34536",
  "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.str-el"
    ],
    [
      "openalex",
      "3104|Advanced Condensed Matter Physics"
    ]
  ],
  "openalex": "W7223841660",
  "pdf_url": "https://arxiv.org/pdf/2610.34536",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-25",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6b7je6zddv9m4.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2610.34536",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.34536"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Quasiparticle Interactions in the $S = 1/2$ Heisenberg Antiferromagnetic Chain CuPzN",
  "title_text": "Quasiparticle Interactions in the S = 1/2 Heisenberg Antiferromagnetic Chain CuPzN",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/6b7je6zddv9m4",
  "venue": "arXiv",
  "versions": []
}