{
  "id": "1202.6602",
  "version": "v1",
  "published": "2012-02-29T17:01:18.000Z",
  "updated": "2012-02-29T17:01:18.000Z",
  "title": "Spin-transfer torque and spin-polarization in topological-insulator/ferromagnet vertical heterostructures",
  "authors": [
    "Farzad Mahfouzi",
    "Naoto Nagaosa",
    "Branislav K. Nikolic"
  ],
  "comment": "5 pages, 3 figures, PDFLaTeX",
  "journal": "Phys. Rev. Lett. 109, 166602 (2012)",
  "doi": "10.1103/PhysRevLett.109.166602",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "We predict an unconventional spin-transfer torque (STT) acting on the magnetization of a free ferromagnetic (F) layer within N/TI/F vertical heterostructures which originates from strong spin-orbit coupling (SOC) on the surface of a three-dimensional topological insulator (TI), as well as from charge current becoming spin-polarized in the direction of transport as it flows from the normal metal (N) across the bulk of the TI slab. Unlike conventional STT in symmetric F'/I/F magnetic tunnel junctions, where only the in-plane STT component is non-zero in the linear response, both the in-plane and perpendicular torque are sizable in N/TI/F junctions while not requiring fixed F' layer as spin-polarizer which is advantageous for spintronic applications. Using the nonequilibrium Born-Oppenheimer treatment of interaction between fast conduction electrons and slow magnetization, we derive a general Keldysh Green function-based STT formula which makes it possible to analyze torque in the presence of SOC either in the bulk or at the interface of the free F layer.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2012-02-29T17:01:18.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "72.25.Mk",
      "72.10.Bg",
      "75.70.Tj",
      "85.75.-d"
    ],
    "keywords": [
      "topological-insulator/ferromagnet vertical heterostructures",
      "spin-transfer torque",
      "keldysh green function-based stt formula",
      "general keldysh green function-based stt",
      "spin-polarization"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review Letters",
      "year": 2012,
      "month": "Oct",
      "volume": 109,
      "number": 16,
      "pages": 166602
    },
    "note": {
      "typesetting": "PDFLaTeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2012PhRvL.109p6602M"
    }
  }
}