论文标题
超导谐振器的稳定性：运动变窄和兰道齐纳（Landau-Zener）驾驶两级缺陷的作用
Stability of superconducting resonators: motional narrowing and the role of Landau-Zener driving of two-level defects
论文作者
论文摘要
超导谐振器和Qubits的频率不稳定性导致逐渐变化和时变能量损失，并阻碍量子处理器调音。它的主要来源是介电噪声源于表面氧化物。为了制定这些波动的全面理解和缓解策略，需要进行详尽的噪声研究。在这里，我们使用频率锁定的循环来跟踪三种不同的谐振器类型的谐振频率抖动---一种氮化氮化物超级电导体，一个铝二氧化铝Coplanar波导和一个铝腔 - 我们观察到了惊人的相似的随机传统 - 随机 - 纤维电脑信号信号波动。在低微波驱动功率下，谐振器表现出多个不稳定的频率位置，这是由于谐振器的单个两级系统缺陷引起的动作狭窄而增加了电源成频率。在所有三个设备中，我们都探测了一个主要的波动器，发现其振幅随着驱动功率的增加而饱和，但是其特征切换速率遵循了准经典的Landau-Zener跃迁的幂律依赖性。
Frequency instability of superconducting resonators and qubits leads to dephasing and time-varying energy-loss and hinders quantum-processor tune-up. Its main source is dielectric noise originating in surface oxides. Thorough noise studies are needed in order to develop a comprehensive understanding and mitigation strategy of these fluctuations. Here we use a frequency-locked loop to track the resonant-frequency jitter of three different resonator types---one niobium-nitride superinductor, one aluminium coplanar waveguide, and one aluminium cavity---and we observe strikingly similar random-telegraph-signal fluctuations. At low microwave drive power, the resonators exhibit multiple, unstable frequency positions, which for increasing power coalesce into one frequency due to motional narrowing caused by sympathetic driving of individual two-level-system defects by the resonator. In all three devices we probe a dominant fluctuator, finding that its amplitude saturates with increasing drive power, but its characteristic switching rate follows the power-law dependence of quasiclassical Landau-Zener transitions.
