{
  "abstract": "Continuous-variable quantum systems offer a natural platform for quantum information processing and analogue quantum simulation of real-world processes. Realising these applications, however, requires anharmonic potentials with programmable functional forms, which are challenging to engineer on demand. Here, in a superconducting harmonic oscillator coupled to a transmon qubit, we construct programmable non-Gaussian phase gates $e^{-iV(\\hat{X})}$, corresponding to the impulsive action of an anharmonic potential $V(\\hat{X})$, and characterise them by reconstructing their corresponding force pointwise. Using bosonic quantum signal processing, we compile target potentials into modular circuits of qubit rotations interleaved with a fixed conditional-displacement primitive. We first demonstrate a cubic phase gate whose cubic nature is jointly validated by the resulting non-Gaussian states and the force reconstructed pointwise from the gate's action on coherent probe states. We then construct a family of double-well potentials and use the reconstructed force to witness the double-well topology and tunable asymmetry. Finally, we engineer an approximate Morse potential and obtain its force profile using position-compressed probes, which extend reliable reconstruction towards the steep repulsive wall. These results establish a programmable route to constructing the potential landscape of quantum harmonic oscillators and a practical method for reconstructing its spatial structure, providing a building block for quantum simulation of anharmonic dynamics.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.02405",
  "author_total": 12,
  "authors": [
    {
      "name": "Clara Yun Fontaine"
    },
    {
      "name": "Mansi Somani"
    },
    {
      "name": "Kehui Yu"
    },
    {
      "name": "May Chee Loke"
    },
    {
      "name": "Jonathan Schwinger"
    },
    {
      "name": "Pak-Tik Fong"
    },
    {
      "name": "Ni-Ni Huang"
    },
    {
      "name": "Adrian Copetudo"
    },
    {
      "name": "Mustafa Bakr"
    },
    {
      "name": "Hoi-Kwan Lau"
    },
    {
      "name": "Tanjung Krisnanda"
    },
    {
      "name": "Yvonne Y. Gao"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0tmfqzcvkgfd7.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.02405",
  "fulltext_url": null,
  "id": "0tmfqzcvkgfd7",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.02405",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Information and Cryptography"
    ]
  ],
  "openalex": "W7207622984",
  "pdf_url": "https://arxiv.org/pdf/2609.02405",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0tmfqzcvkgfd7.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:18Z",
      "native_id": "2609.02405",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.02405"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Constructing and characterising anharmonic potentials in a harmonic oscillator",
  "title_text": "Constructing and characterising anharmonic potentials in a harmonic oscillator",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:18Z",
  "url": "https://research.draconitic.com/paper/0tmfqzcvkgfd7",
  "venue": "arXiv",
  "versions": []
}