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arXiv · 2407.15783

24 days-stable CNOT-gate on fluxonium qubits with over 99.9% fidelity

Wei-Ju Lin·Hyunheung Cho·Yinqi Chen·Maxim G. Vavilov·Chen Wang·Vladimir E. Manucharyan
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Abstract

Fluxonium qubit is a promising building block for quantum information processing due to its long coherence time and strong anharmonicity. In this paper, we realize a 60 ns direct CNOT-gate on two inductively-coupled fluxonium qubits using selective darkening approach, resulting in a gate fidelity as high as 99.94%. The fidelity remains above 99.9% for 24 days without any recalibration between randomized benchmarking measurements. Compared with the 99.96% fidelity of a 60 ns identity gate, our data brings the investigation of the non-decoherence-related errors during gate operations down to $2 \times 10^{-4}$. The present result adds a simple and robust two-qubit gate into the still relatively small family of "the beyond three nines" demonstrations on superconducting qubits.

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Wei-Ju Lin, Hyunheung Cho, Yinqi Chen, Maxim G. Vavilov, Chen Wang, Vladimir E. Manucharyan. 2024-07-22. 24 days-stable CNOT-gate on fluxonium qubits with over 99.9% fidelity. https://arxiv.org/abs/2407.15783

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