{
  "id": "2203.02436",
  "version": "v1",
  "published": "2022-03-04T17:10:55.000Z",
  "updated": "2022-03-04T17:10:55.000Z",
  "title": "Bending the rules of low-temperature thermometry with periodic driving",
  "authors": [
    "Jonas Glatthard",
    "Luis A. Correa"
  ],
  "comment": "9 + 6 pages, 3 figures",
  "categories": [
    "quant-ph",
    "cond-mat.quant-gas",
    "cond-mat.stat-mech"
  ],
  "abstract": "There exist severe limitations on the accuracy of low-temperature thermometry, which poses a major challenge for future quantum-technological applications. Low-temperature sensitivity might be manipulated by tailoring the interactions between probe and sample. Unfortunately, the tunability of these interactions is usually very restricted. Here, we focus on a more practical solution to boost thermometric precision -- driving the probe. Specifically, we solve for the limit cycle of a periodically modulated linear probe in an equilibrium sample. We treat the probe-sample interactions \\textit{exactly} and hence, our results are valid for arbitrarily low temperatures $ T $ and any spectral density. We find that weak near-resonant modulation strongly enhances the signal-to-noise ratio of low-temperature measurements, while causing minimal back action on the sample. Furthermore, we show that near-resonant driving changes the power law that governs thermal sensitivity over a broad range of temperatures, thus `bending' the fundamental precision limits and enabling more sensitive low-temperature thermometry. We then focus on a concrete example -- impurity thermometry in an atomic condensate. We demonstrate that periodic driving allows for a sensitivity improvement of several orders of magnitude in sub-nanokelvin temperature estimates drawn from the density profile of the impurity atoms. We thus provide a feasible upgrade that can be easily integrated into low-$T$ thermometry experiments.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-03-04T17:10:55.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "low-temperature thermometry",
      "periodic driving",
      "sub-nanokelvin temperature estimates drawn",
      "weak near-resonant modulation strongly enhances",
      "fundamental precision limits"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 6,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}