论文标题
观众量松弛引起的有效量子
Effective qubit dephasing induced by spectator-qubit relaxation
论文作者
论文摘要
在许多用于量子计算的领先体系结构中，如果我们可以将分离的单量相干时间等同于在多Qubit设备中测得的相干时间的单量相干时间。在多Qubit的超导电路平台上，由于观众Qubits的自发放松与控制Qubit的自发放松，我们显示了控制量子保持量子的降低速率的提高。由于观众弛豫与控制谱Z-Z-相互作用之间的相互作用，我们将这种增加的dephasing归因于随机Z相踢的随机Z相踢。我们使用Ramsey衰变实验测量了这种额外的次数的大小，展示如何通过动态解耦脉冲序列进行校正，并证明随机基准测试对效果不敏感。我们的实验结果得到了一个可靠的理论模型的支持，该模型捕获了任意数量的观众量子，并为增强的dephasing背后的机制提供了简单，直观的图片。
In many leading architectures for quantum computing, it remains to be understood if we can equate single-qubit coherence times measured in isolation, to that of coherence times measured in multi-qubit devices. On a multi-qubit superconducting circuit platform we show an increase in the dephasing rate of a control qubit due to the spontaneous relaxation of spectator qubits coupled to the control qubit. We attribute this increased dephasing to random in time Z-phase kicks on the control qubit due to the interplay between spectator relaxation and the control-spectator ZZ- interaction. We measure the magnitude of this extra dephasing using Ramsey decay experiments, show how it can be corrected via dynamical decoupling pulse sequences, and demonstrate that randomized benchmarking is insensitive to the effect. Our experimental results are supported by a robust theoretical model that captures an arbitrary number of spectator qubits, and gives a simple, intuitive picture for the mechanism behind the enhanced dephasing.
