Inductively shunted transmons exhibit noise insensitive plasmon states and a fluxon decay exceeding 3 hours

article Inductively shunted transmons exhibit noise insensitive plasmon states and a fluxon decay exceeding 3 hours published yes Farid Hassani author 2AED110C-F248-11E8-B48F-1D18A9856A870000-0001-6937-5773 Matilda Peruzzo author 3F920B30-F248-11E8-B48F-1D18A9856A870000-0002-3415-4628 Lucky Kapoor author 84b9700b-15b2-11ec-abd3-831089e676150000-0001-8319-2148 Andrea Trioni author 42F71B44-F248-11E8-B48F-1D18A9856A87 Martin Zemlicka author 2DCF8DE6-F248-11E8-B48F-1D18A9856A870009-0005-0878-3032 Johannes M Fink author 4B591CBA-F248-11E8-B48F-1D18A9856A870000-0001-8112-028X JoFi department Hybrid Semiconductor - Superconductor Quantum Devices project QUANTUM INFORMATION SYSTEMS BEYOND CLASSICAL CAPABILITIES / P5- Integration of Superconducting Quantum Circuits project Currently available quantum processors are dominated by noise, which severely limits their applicability and motivates the search for new physical qubit encodings. In this work, we introduce the inductively shunted transmon, a weakly flux-tunable superconducting qubit that offers charge offset protection for all levels and a 20-fold reduction in flux dispersion compared to the state-of-the-art resulting in a constant coherence over a full flux quantum. The parabolic confinement provided by the inductive shunt as well as the linearity of the geometric superinductor facilitates a high-power readout that resolves quantum jumps with a fidelity and QND-ness of >90% and without the need for a Josephson parametric amplifier. Moreover, the device reveals quantum tunneling physics between the two prepared fluxon ground states with a measured average decay time of up to 3.5 h. In the future, fast time-domain control of the transition matrix elements could offer a new path forward to also achieve full qubit control in the decay-protected fluxon basis. https://research-explorer.ista.ac.at/download/13227/13248/2023_NatureComm_Hassani.pdf application/pdfno Springer Nature2023 eng Nature Communications 2041-1723 37407570 00102472990000910.1038/s41467-023-39656-2 14 https://research-explorer.ista.ac.at/record/17133 F. Hassani, M. Peruzzo, L. Kapoor, A. Trioni, M. Zemlicka, J.M. Fink, Nature Communications 14 (2023). Hassani, Farid, et al. “Inductively Shunted Transmons Exhibit Noise Insensitive Plasmon States and a Fluxon Decay Exceeding 3 Hours.” Nature Communications, vol. 14, 3968, Springer Nature, 2023, doi:<a href="https://doi.org/10.1038/s41467-023-39656-2">10.1038/s41467-023-39656-2</a>. F. Hassani, M. Peruzzo, L. Kapoor, A. Trioni, M. Zemlicka, and J. M. Fink, “Inductively shunted transmons exhibit noise insensitive plasmon states and a fluxon decay exceeding 3 hours,” Nature Communications, vol. 14. Springer Nature, 2023. Hassani, Farid, Matilda Peruzzo, Lucky Kapoor, Andrea Trioni, Martin Zemlicka, and Johannes M Fink. “Inductively Shunted Transmons Exhibit Noise Insensitive Plasmon States and a Fluxon Decay Exceeding 3 Hours.” Nature Communications. Springer Nature, 2023. <a href="https://doi.org/10.1038/s41467-023-39656-2">https://doi.org/10.1038/s41467-023-39656-2</a>. Hassani, F., Peruzzo, M., Kapoor, L., Trioni, A., Zemlicka, M., & Fink, J. M. (2023). Inductively shunted transmons exhibit noise insensitive plasmon states and a fluxon decay exceeding 3 hours. Nature Communications. Springer Nature. <a href="https://doi.org/10.1038/s41467-023-39656-2">https://doi.org/10.1038/s41467-023-39656-2</a> Hassani F, Peruzzo M, Kapoor L, Trioni A, Zemlicka M, Fink JM. 2023. Inductively shunted transmons exhibit noise insensitive plasmon states and a fluxon decay exceeding 3 hours. Nature Communications. 14, 3968. Hassani F, Peruzzo M, Kapoor L, Trioni A, Zemlicka M, Fink JM. Inductively shunted transmons exhibit noise insensitive plasmon states and a fluxon decay exceeding 3 hours. Nature Communications. 2023;14. doi:<a href="https://doi.org/10.1038/s41467-023-39656-2">10.1038/s41467-023-39656-2</a> 132272023-07-16T22:01:08Z2026-04-15T06:39:57Z