论文标题
在驱动的磁通量Qubit中，相干时间的Floquet工程增强
Floquet-engineered enhancement of coherence times in a driven fluxonium qubit
论文作者
论文摘要
我们使用磁通量超导电路定期驱动以用动态诱导的通量不敏感的甜点编码量子信息时出现的准结构。 Floquet理论的框架提供了这些高稳态工作点的直观描述，该工作点远离未划分量子的半频率对称点。这种方法在选择磁通偏置点和逻辑量子位的能量方面具有灵活性，如[\ textit {Huang等，2020}]中所示。我们表征了系统对调制振幅和直流通量偏置噪声的响应，并在实验上证明了一个最佳的工作点，这同时对两者的波动都不敏感。与在同一偏置点处的静态操作相比，我们观察到用拉姆齐型干涉测量测量的量子相干时间的40倍增强。
We use the quasienergy structure that emerges when a fluxonium superconducting circuit is driven periodically to encode quantum information with dynamically induced flux-insensitive sweet spots. The framework of Floquet theory provides an intuitive description of these high-coherence working points located away from the half-flux symmetry point of the undriven qubit. This approach offers flexibility in choosing the flux bias point and the energy of the logical qubit states as shown in [\textit{Huang et al., 2020}]. We characterize the response of the system to noise in the modulation amplitude and DC flux bias, and experimentally demonstrate an optimal working point which is simultaneously insensitive against fluctuations in both. We observe a 40-fold enhancement of the qubit coherence times measured with Ramsey-type interferometry at the dynamical sweet spot compared with static operation at the same bias point.
