{
  "abstract": "We compute the specific absorption rate of a uniaxial single-domain nanomagnet driven by an alternating magnetic field by two methods: i) direct numerical integration of the stochastic (Langevin) Landau--Lifshitz--Gilbert equation (the LLL approach), and ii) linear response theory (LRT) based on the Debye susceptibility with the Néel relaxation time $\\ta$. We first analytically show that both methods are equivalent for small magnetic field amplitude, and then compute their deviation $Λ\\equiv\\SAR_{\\LLL}/\\SAR_{\\LRT}-1$ as a function of the magnetic field amplitude for two temperatures chosen on opposite sides of the Debye resonance. One of the main results is that the sign and magnitude of $Λ$ are governed by the dimensionless product $\\om\\ta$, in addition to the linearity parameter $ξ=μ_{s}B_{0}/k_{B}T$ for the easy-axis geometry considered here. Indeed, below resonance ($\\om\\ta<1$), linear response theory overestimates the specific absorption rate, whereas above resonance ($\\om\\ta>1$, the regime typical of blocked nanoparticles) linear response theory can underestimate the specific absorption rate by up to $\\sim70\\%$ at $ξ\\sim2$. We expect this work to provide a quantitative guidance for the use of linear response theory in magnetic hyperthermia and related nanoscale heat-transport problems, and to serve as a single-particle benchmark for extensions to many-spin and interacting systems.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.27351",
  "author_total": 1,
  "authors": [
    {
      "name": "H. Kachkachi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/56q5r0n3whf2c.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.27351",
  "fulltext_url": null,
  "id": "56q5r0n3whf2c",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.27351",
  "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",
      "cond-mat.mes-hall"
    ],
    [
      "openalex",
      "2204|Characterization and Applications of Magnetic Nanoparticles"
    ]
  ],
  "openalex": "W7166067854",
  "pdf_url": "https://arxiv.org/pdf/2606.27351",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/56q5r0n3whf2c.ris",
  "sources": [
    {
      "first_seen": "2026-11-06T18:21:30Z",
      "native_id": "2606.27351",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.27351"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Specific absorption rate of uniaxial single-domain nanomagnets: stochastic spin dynamics versus linear response theory",
  "title_text": "Specific absorption rate of uniaxial single-domain nanomagnets: stochastic spin dynamics versus linear response theory",
  "type": "preprint",
  "updated_at": "2026-11-09T00:20:33Z",
  "url": "https://research.draconitic.com/paper/56q5r0n3whf2c",
  "venue": "arXiv",
  "versions": []
}