{
  "id": "2303.07025",
  "version": "v1",
  "published": "2023-03-13T11:42:37.000Z",
  "updated": "2023-03-13T11:42:37.000Z",
  "title": "Experimental investigation of the effect of topological insulator on the magnetization dynamics of ferromagnetic metal: $BiSbTe_{1.5}Se_{1.5}$ and $Ni_{80}Fe_{20}$ heterostructure",
  "authors": [
    "Sayani Pal",
    "Soumik Aon",
    "Subhadip Manna",
    "Sambhu G Nath",
    "Kanav Sharma",
    "Chiranjib Mitra"
  ],
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "We have studied ferromagnetic metal/topological insulator bilayer system to understand magnetization dynamics of ferromagnetic metal (FM) in contact with a topological insulator (TI). At magnetic resonance condition, the precessing magnetization in the metallic ferromagnet ($Ni_{80}Fe_{20}$) injects spin current into the topological insulator ($BiSbTe_{1.5}Se_{1.5}$), a phenomenon known as spin-pumping. Due to the spin pumping effect, fast relaxation in the ferromagnet results in the broadening of ferromagnetic resonance linewidth ($\\Delta H$). We evaluated the parameters like effective Gilbert damping coefficient ($\\alpha_{eff}$), spin-mixing conductance ($g_{eff}^{\\uparrow \\downarrow}$) and spin current density ($j_S^0$) to confirm a successful spin injection due to spin-pumping into the $BiSbTe_{1.5}Se_{1.5}$ layer. TIs embody a spin-momentum locked surface state that span the bulk band-gap. It can act differently to the FM magnetization than the other normal metals. To probe the effect of topological surface state, a systematic low temperature study is crucial as surface state of TI dominates at lower temperatures. The exponential growth of $\\Delta H$ for all different thickness combination of FM/TI bilayers and effective Gilbert damping coefficient ($\\alpha_{eff}$) with lowering temperature confirms the prediction that spin chemical bias generated from spin-pumping induces surface current in TI due to spin-momentum locking. The hump-like feature of magnetic anisotropy field ($H_K$)of the bilayer around 60K suggests that the decrease of interfacial in-plane magnetic anisotropy can result from exchange coupling between the TI surface state and the local moments of FM layer.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-03-13T11:42:37.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "magnetization dynamics",
      "ferromagnetic metal",
      "surface state",
      "experimental investigation",
      "metal/topological insulator bilayer system"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}