论文标题
两流头国峰交叉谐振门的演示
Demonstration of the Two-Fluxonium Cross-Resonance Gate
论文作者
论文摘要
超导磁盘量子置量量子具有较长的相干时间和在半通量量子甜点处的高量子门的巨大潜力。但是，目前两倍闸门的实施通过需要非竞争状态的临时人群或从最佳位置调整磁通量来损害Fluxonium的相干性能。在这里，我们认识到两个电容耦合的磁通量之间的一个快速的全微波交叉呼吸门，其量子动力学非常局限于计算空间。我们演示了70 ns中的直接CNOT门，尽管限制了次优最佳的测量设置和设备相干性的限制，但具有$ \ MATHCAL {F} = 0.9949（6）$的忠诚度。我们的结果项目可能是将两量价错误率降低到$ 10^{ - 4} $的可能途径，并使用当今的技术。
The superconducting fluxonium qubit has a great potential for high-fidelity quantum gates with its long coherence times and strong anharmonicity at the half flux quantum sweet spot. However, current implementations of two-qubit gates compromise fluxonium's coherence properties by requiring either a temporary population of the non-computational states or tuning the magnetic flux off the sweet spot. Here we realize a fast all-microwave cross-resonance gate between two capacitively-coupled fluxoniums with the qubit dynamics well confined to the computational space. We demonstrate a direct CNOT gate in 70 ns with fidelity up to $\mathcal{F}=0.9949(6)$ despite the limitations of a sub-optimal measurement setup and device coherence. Our results project a possible pathway towards reducing the two-qubit error rate below $10^{-4}$ with present-day technologies.
