{
  "id": "2107.03192",
  "version": "v1",
  "published": "2021-07-07T13:05:47.000Z",
  "updated": "2021-07-07T13:05:47.000Z",
  "title": "A hole-Cr$^{+}$ nano-magnet in a semiconductor quantum dot",
  "authors": [
    "V. Tiwari",
    "M. Arino",
    "S. Gupta",
    "M. Morita",
    "T. Inoue",
    "D. Caliste",
    "P. Pochet",
    "H. Boukari",
    "S. Kuroda",
    "L. Besombes"
  ],
  "categories": [
    "cond-mat.mes-hall",
    "quant-ph"
  ],
  "abstract": "We study a new diluted magnetic semiconductor system based on the spin of the ionized acceptor Cr$^+$. We show that the negatively charged Cr$^+$ ion, an excited state of the Cr in II-VI semiconductor, can be stable when inserted in a CdTe quantum dot (QD). The Cr$^+$ attracts a heavy-hole in the QD and form a stable hole-Cr$^+$ complex. Optical probing of this system reveals a ferromagnetic coupling between heavy-holes and Cr$^+$ spins. At low temperature, the thermalization on the ground state of the hole-Cr$^+$ system with parallel spins prevents the optical recombination of the excess electron on the 3$d$ shell of the atom. We study the dynamics of the nano-magnet formed by the hole-Cr$^+$ exchange interaction. The ferromagnetic ground states with M$_z$=$\\pm$4 can be controlled by resonant optical pumping and a spin relaxation time in the 20 $\\mu$s range is obtained at T=4.2 K. This spin memory at zero magnetic field is limited by the interaction with phonons.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-07-07T13:05:47.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "semiconductor quantum dot",
      "nano-magnet",
      "zero magnetic field",
      "spin relaxation time",
      "ferromagnetic ground states"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}