2024/07/22 by Wei-Ju Lin, Lin, Wei-Ju, Hyunheung Cho +9 · 8 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum Physics (quant-ph) #Quantum and electron transport phenomena #Quantum optics and atomic interactions
paper · pdf · doi:10.48550/arxiv.2407.15783
openalex publication_date 2024/07/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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 × 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.