{
  "id": "2003.09131",
  "version": "v1",
  "published": "2020-03-20T07:44:12.000Z",
  "updated": "2020-03-20T07:44:12.000Z",
  "title": "Electron Spin Resonance with up to 20 Spin Sensitivity Measured using a Superconducting Flux Qubit",
  "authors": [
    "Rangga P. Budoyo",
    "Kosuke Kakuyanagi",
    "Hiraku Toida",
    "Yuichiro Matsuzaki",
    "Shiro Saito"
  ],
  "comment": "4 pages, 4 figures",
  "categories": [
    "quant-ph",
    "cond-mat.mes-hall",
    "cond-mat.supr-con"
  ],
  "abstract": "We report on electron spin resonance spectroscopy measurements using a superconducting flux qubit with a sensing volume of 6 fl. The qubit is read out using a frequency-tunable Josephson bifurcation amplifier, which leads to an inferred measurement sensitivity of about 20 spins in a 1 s measurement. This sensitivity represents an order of magnitude improvement when compared with flux-qubit schemes using a dc-SQUID switching readout. Furthermore, noise spectroscopy reveals that the sensitivity is limited by flicker ($1/f$) flux noise.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-03-20T07:44:12.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "superconducting flux qubit",
      "spin sensitivity",
      "electron spin resonance spectroscopy measurements",
      "frequency-tunable josephson bifurcation amplifier"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}