论文标题
高动力学电容电路中多级动力和变质的表征
Characterization of multi-level dynamics and decoherence in a high-anharmonicity capacitively shunted flux circuit
论文作者
论文摘要
我们介绍了具有三个大型分流电容器的三约瑟夫森结 - 连接环路的设计和表征。该电路用作量子，显示了长度的能量放电时间，其顺序为40 $ {\ unicode [times] {x3bc}}} $ s和一个9.4 $ {\ unicode [times] {times] {x3bc}}} $ s的旋转回声时间为9.4 $ {\ unicode [times]该电路具有高的非谐度，为2 $π$$ \ times $ 3.69 GHz。我们提取用作QUTRIT的电路的多级松弛和脱位速率，并讨论折叠的可能来源。高的非谐调允许使用纳秒范围的栅极持续时间和测量的99.92％的平均栅极保真度，以随机基准测试为特征。这些结果表明，对于快速纳米级时尺度的两分门和多级量子逻辑的潜在用途。
We present the design and characterization of a three-Josephson-junction superconducting loop circuit with three large shunt capacitors. Used as a qubit, the circuit shows long energy-relaxation times, of the order of 40 ${ \unicode[Times]{x3BC}}$s and a spin-echo dephasing time of 9.4 ${ \unicode[Times]{x3BC}}$s. The circuit has high anharmonicity, of 2$π$$\times$3.69 GHz. We extract the multilevel relaxation and dephasing rates of the circuit used as a qutrit and discuss the possible sources for the decoherence. The high anharmonicity allows for fast qubit control with nanosecond-range gate durations and a measured average gate fidelity of 99.92%, characterized by randomized benchmarking. These results demonstrate interesting potential use for fast nanosecond-time-scale two-qubit gates and multilevel quantum logic.
