{
  "id": "2005.01925",
  "version": "v1",
  "published": "2020-05-05T03:04:19.000Z",
  "updated": "2020-05-05T03:04:19.000Z",
  "title": "Dimensional crossover in spin Hall oscillators",
  "authors": [
    "Andrew Smith",
    "Kemal Sobotkiewich",
    "Amanatullah Khan",
    "Eric A. Montoya",
    "Liu Yang",
    "Zheng Duan",
    "Tobias Schneider",
    "Kilian Lenz",
    "Jürgen Lindner",
    "Kyongmo An",
    "Xiaoqin Li",
    "Ilya N. Krivorotov"
  ],
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "Auto-oscillations of magnetization driven by direct spin current have been previously observed in multiple quasi-zero-dimensional (0D) ferromagnetic systems such as nanomagnets and nanocontacts. Recently, it was shown that pure spin Hall current can excite coherent auto-oscillatory dynamics in quasi-one-dimensional (1D) ferromagnetic nanowires but not in quasi-two-dimensional (2D) ferromagnetic films. Here we study the 1D to 2D dimensional crossover of current-driven magnetization dynamics in wire-based Pt/$\\mathrm{Ni}_{80}\\mathrm{Fe}_{20}$ bilayer spin Hall oscillators via varying the wire width. We find that increasing the wire width results in an increase of the number of excited auto-oscillatory modes accompanied by a decrease of the amplitude and coherence of each mode. We also observe a crossover from a hard to a soft onset of the auto-oscillations with increasing the wire width. The amplitude of auto-oscillations rapidly decreases with increasing temperature suggesting that interactions of the phase-coherent auto-oscillatory modes with incoherent thermal magnons plays an important role in suppression of the auto-oscillatory dynamics. Our measurements set the upper limit on the dimensions of an individual spin Hall oscillator and elucidate the mechanisms leading to suppression of coherent auto-oscillations with increasing oscillator size.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-05-05T03:04:19.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dimensional crossover",
      "incoherent thermal magnons plays",
      "auto-oscillatory modes",
      "auto-oscillations",
      "bilayer spin hall oscillators"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}