{
  "abstract": "Two-dimensional van der Waals ferromagnets Fe$_3$GeTe$ _2$ (F3GT) and Fe$_5$GeTe$_2$ (F5GT) exhibit pronounced magneto-optical responses, which open promising platforms for investigating the interplay among lattice, electronic, and magnetic degrees of freedom. Here, we present a comparative study of optical resonance-induced anisotropic electron-phonon coupling and its association with magnetic ordering in these systems using wavelength- and temperature-dependent helicity-resolved Raman spectroscopy. By resolving the doubly degenerate E modes under left- and right-circularly polarized excitations, we demonstrate that the temperature evolution of the chiral mode splitting ($Δf$) does not track the magnetization behavior, indicating that the helicity-dependent Raman response arises not solely from time-reversal symmetry breaking due to magnetic order, but also from spin-orbit-coupled electronic interactions. Notably, in F3GT, the out-of-plane magnetization indirectly governs the in-plane anisotropic electron-phonon coupling under optical resonance, whereas F5GT exhibits static anisotropic interactions. The Fano asymmetry parameter $1/q$ reveals mode- and temperature-dependent coupling strengths between phonons and the electronic continuum, with pronounced angular anisotropy in F3GT but isotropic behavior in F5GT--- a consequence of its multiple Fe sites and enhanced interlayer hybridization in the latter. Our results demonstrate the role of crystal structure and magnetic anisotropy in shaping the anisotropically coupled electron-phonon-spin dynamics in these layered metallic ferromagnets, and highlight Fe$_n$GeTe$_2$ as a versatile platform for microscopic insight into chiral light-matter interactions in layered metallic ferromagnets.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.03193",
  "author_total": 7,
  "authors": [
    {
      "name": "Smrutiranjan Mekap"
    },
    {
      "name": "Jyoti Saini"
    },
    {
      "name": "Andrzej Ptok"
    },
    {
      "name": "Pawan Kumar Srivastava"
    },
    {
      "name": "Changgu Lee"
    },
    {
      "name": "Subhasis Ghosh"
    },
    {
      "name": "Anushree Roy"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d4gq9kprjvp28.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.03193",
  "fulltext_url": null,
  "id": "d4gq9kprjvp28",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.03193",
  "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",
      "cond-mat.str-el"
    ],
    [
      "openalex",
      "2505|2D Materials and Applications"
    ]
  ],
  "openalex": "W7172513715",
  "pdf_url": "https://arxiv.org/pdf/2608.03193",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/d4gq9kprjvp28.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2608.03193",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.03193"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Contrasting anisotropic electron-phonon-spin coupling in Fe$_{3}$GeTe$_{2}$ and Fe$_{5}$GeTe$_{2}$: A helicity-resolved Raman study",
  "title_text": "Contrasting anisotropic electron-phonon-spin coupling in Fe_3GeTe_2 and Fe_5GeTe_2: A helicity-resolved Raman study",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/d4gq9kprjvp28",
  "venue": "arXiv",
  "versions": []
}