{
  "id": "2308.07849",
  "version": "v1",
  "published": "2023-08-15T15:53:45.000Z",
  "updated": "2023-08-15T15:53:45.000Z",
  "title": "High-frequency suppression of inductive coupling between flux qubit and transmission line resonator",
  "authors": [
    "Sahel Ashhab",
    "Ziqiao Ao",
    "Fumiki Yoshihara",
    "Kouichi Semba"
  ],
  "comment": "24 pages (preprint), 5 figures",
  "categories": [
    "quant-ph",
    "cond-mat.supr-con"
  ],
  "abstract": "We perform theoretical calculations to investigate the naturally occurring high-frequency cutoff in a circuit comprising a flux qubit coupled inductively to a transmission line resonator (TLR). Our results agree with those of past studies that considered somewhat similar circuit designs. In particular, a decoupling occurs between the qubit and the high-frequency modes. As a result, the coupling strength between the qubit and resonator modes increases with mode frequency $\\omega$ as $\\sqrt{\\omega}$ at low frequencies and decreases as $1/\\sqrt{\\omega}$ at high frequencies. We derive expressions for the multimode-resonator-induced Lamb shift in the qubit's characteristic frequency. Because of the natural decoupling between the qubit and high-frequency modes, the Lamb-shift-renormalized qubit frequency remains finite.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-08-15T15:53:45.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "transmission line resonator",
      "flux qubit",
      "high-frequency suppression",
      "inductive coupling",
      "lamb-shift-renormalized qubit frequency remains finite"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 24,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}