Unimon qubit

Loading...
Thumbnail Image

Access rights

openAccess
publishedVersion

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Major/Subject

Mcode

Degree programme

Language

en

Pages

Series

Nature Communications, Volume 13, issue 1

Abstract

Superconducting qubits seem promising for useful quantum computers, but the currently wide-spread qubit designs and techniques do not yet provide high enough performance. Here, we introduce a superconducting-qubit type, the unimon, which combines the desired properties of increased anharmonicity, full insensitivity to dc charge noise, reduced sensitivity to flux noise, and a simple structure consisting only of a single Josephson junction in a resonator. In agreement with our quantum models, we measure the qubit frequency, ω01/(2π), and increased anharmonicity α/(2π) at the optimal operation point, yielding, for example, 99.9% and 99.8% fidelity for 13 ns single-qubit gates on two qubits with (ω01, α) = (4.49 GHz, 434 MHz) × 2π and (3.55 GHz, 744 MHz) × 2π, respectively. The energy relaxation seems to be dominated by dielectric losses. Thus, improvements of the design, materials, and gate time may promote the unimon to break the 99.99% fidelity target for efficient quantum error correction and possible useful quantum advantage with noisy systems.

Description

Funding Information: S.K., A.G., O.K., V.V., and M.M. acknowledge funding from the European Research Council under Consolidator Grant No. 681311 (QUESS) and Advanced Grant No. 101053801 (ConceptQ), European Commission through H2020 program projects QMiCS (grant agreement 820505, Quantum Flagship), the Academy of Finland through its Centers of Excellence Program (project Nos. 312300, and 336810), and Business Finland through its Quantum Technologies Industrial grant No. 41419/31/2020. S.K. and M.M. acknowledge Research Impact Foundation for grant No. 173 (CONSTI). E.H. thanks Emil Aaltonen Foundation (grant No. 220056 K) and Nokia Foundation (grant No. 20230659) for funding. We acknowledge the provision of facilities and technical support by Aalto University at OtaNano - Micronova Nanofabrication Center and LTL infrastructure which is part of European Microkelvin Platform (EMP, No. 824109 EU Horizon 2020). We thank the whole staff at IQM and QCD Labs for their support. Especially, we acknowledge the help with the experimental setup from Roope Kokkoniemi, code and software support from Joni Ikonen, Tuukka Hiltunen, Shan Jolin, Miikka Koistinen, Jari Rosti, Vasilii Sevriuk, and Natalia Vorobeva, and useful discussions with Brian Tarasinski. | openaire: EC/H2020/681311/EU//QUESS | openaire: EC/HE/101053801/EU//ConceptQ

Keywords

Other note

Citation

Hyyppä, E, Kundu, S, Chan, C F, Gunyhó, A, Hotari, J, Janzso, D, Juliusson, K, Kiuru, O, Kotilahti, J, Landra, A, Liu, W, Marxer, F, Mäkinen, A, Orgiazzi, J L, Palma, M, Savytskyi, M, Tosto, F, Tuorila, J, Vadimov, V, Li, T, Ockeloen-Korppi, C, Heinsoo, J, Tan, K Y, Hassel, J & Möttönen, M 2022, 'Unimon qubit', Nature Communications, vol. 13, no. 1, 6895. https://doi.org/10.1038/s41467-022-34614-w