{
  "id": "1908.06055",
  "version": "v1",
  "published": "2019-08-16T16:48:22.000Z",
  "updated": "2019-08-16T16:48:22.000Z",
  "title": "Itinerant ferromagnetism and intrinsic anomalous Hall effect in amorphous iron-germanium",
  "authors": [
    "D. S. Bouma",
    "Z. Chen",
    "B. Zhang",
    "F. Bruni",
    "M. E. Flatté",
    "R. Streubel",
    "L. -W. Wang",
    "R. Q. Wu",
    "F. Hellman"
  ],
  "comment": "9 pages, 8 figures",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci"
  ],
  "abstract": "The amorphous iron-germanium system ($a$-Fe$_x$Ge$_{1-x}$) lacks long-range structural order and hence lacks a meaningful Brillouin zone. The magnetization of $a$-Fe$_x$Ge$_{1-x}$ is well explained by the Stoner model for Fe concentrations $x$ above the onset of magnetic order around $x=0.4$, indicating that the local order of the amorphous structure preserves the spin-split density of states of the Fe-$3d$ states sufficiently to polarize the electronic structure despite $\\mathbf{k}$ being a bad quantum number. Measurements reveal an enhanced anomalous Hall resistivity $\\rho_{xy}^{\\mathrm{AH}}$ relative to crystalline FeGe; this $\\rho_{xy}^{\\mathrm{AH}}$ is compared to density functional theory calculations of the anomalous Hall conductivity to resolve its underlying mechanisms. The intrinsic mechanism, typically understood as the Berry curvature integrated over occupied $\\mathbf{k}$-states but equivalent to the density of curvature integrated over occupied energies in aperiodic materials, dominates the anomalous Hall conductivity of $a$-Fe$_x$Ge$_{1-x}$ ($0.38 \\leq x \\leq 0.61$).",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-08-16T16:48:22.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "intrinsic anomalous hall effect",
      "amorphous iron-germanium",
      "itinerant ferromagnetism",
      "anomalous hall conductivity",
      "lacks long-range structural order"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}