{
  "id": "1811.03973",
  "version": "v1",
  "published": "2018-11-09T15:30:27.000Z",
  "updated": "2018-11-09T15:30:27.000Z",
  "title": "Enhanced lifetimes of spin chains coupled to chiral edge states",
  "authors": [
    "F. Delgado",
    "J. Fernández-Rossier"
  ],
  "comment": "11 pages, 3 figures",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "We consider spin relaxation of finite-size spin chains exchanged coupled with a one dimensional (1D) electron gas at the edge of a Quantum Spin Hall (QSH) insulator. Spin lifetimes can be enhanced due to two independent mechanisms. First, the suppression of spin-flip forward scattering inherent in the spin momentum locking of the QSH edges. Second, the reduction of spin-flip backward scattering due to destructive interference of the quasiparticle exchange, modulated by $k_F d$, where $d$ is the inter-spin distance and $k_F$ is the Fermi wavenumber of the electron gas. We show that the spin lifetime of the $S=1/2$ ground state of odd-numbered chains of antiferromagnetically (AFM) coupled $S=1/2$ spins can be increased more than 4 orders of magnitude by properly tuning the product $k_Fd$ and the spin size $N$, in strong contrast with the 1D case. Possible physical realizations together with some potential issues are also discussed.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-11-09T15:30:27.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "chiral edge states",
      "enhanced lifetimes",
      "spin lifetime",
      "electron gas",
      "quantum spin hall"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}