Bosonic Error Correction with Fluxonium --> Quantum Physics arXiv:2609.26880 (quant-ph) [Submitted on 22 Sep 2026] Title:Bosonic Error Correction with Fluxonium Authors:Shantanu R. Jha, Shoumik D. Chowdhury, Gabriele Rolleri, Anaida Ali, Lev-Arcady Sellem, Réouven Assouly, David Pahl, Lukas Pahl, Junyoung An, Farid Hassani, Hung-Yu Tsao, Chia-Chin Tsai, Aranya Goswami, Jeremie Boudreault, Jeffrey M. Gertler, Michael A. Gingras, Bethany M. Niedzielski, Jeffrey M. Knecht, Mollie E. Schwartz, Kyle Serniak, Jeffrey A. Grover, Baptiste Royer, Max Hays, William D. Oliver View a PDF of the paper titled Bosonic Error Correction with Fluxonium, by Shantanu R. Jha and 23 other authors View PDF HTML (experimental) Abstract:Bosonic quantum error correction (QEC) offers a hardware-efficient route to fault-tolerant quantum computing. To date, however, superconducting circuit implementations of bosonic codes have utilized centimeter-scale 3D microwave cavities controlled by fixed-frequency transmon qubits, with logical lifetimes limited by transmon bit-flip errors. Here, we realize bosonic QEC in a fully planar architecture by pairing a heavy fluxonium, whose $451 \pm 70~\mu\mathrm{s}$ bit-flip lifetime exceeds that of any control qubit in previous demonstrations, with an on-chip Archimedean spiral resonator several orders of magnitude smaller in mode volume than prior 3D cavities. We prepare finite-energy Gottesman-Kitaev-Preskill (GKP) states and stabilize them using measurement-free error correction with rapid fluxonium reset, extending the logical lifetime by a factor of $1.59 \pm 0.05$. These results provide the first demonstration of resonator control using a weakly coupled fluxonium and, with it, the first realization of standalone bosonic QEC in a fully planar superconducting circuit architecture. Comments: Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2609.26880 [quant-ph] (or arXiv:2609.26880v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2609.26880 Focus to learn more arXiv-
