Identifying capacitive and inductive loss in lumped element superconducting hybrid titanium nitride/aluminum resonators
Identifying capacitive and inductive loss in lumped element superconducting hybrid titanium nitride/aluminum resonators
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DOI：
10.1063/1.4730389
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发表时间：
2012-03
影响因子：
4
通讯作者：
M. Vissers;M. Weides;J. S. Kline;M. Sandberg;D. Pappas
中科院分区：
文献类型：
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作者：
M. Vissers;M. Weides;J. S. Kline;M. Sandberg;D. Pappas
我们提出了一种通过使用混合材料、集总元件器件来系统地定位和提取微波频率超导谐振器中的电容和电感损耗的方法。在这些器件中，叉指电容器和曲折电感器元件中的超低损耗氮化钛逐渐被铝取代。通过测量 50 mK 下每个元素中 Al/TiN 比例增加时的功率相关损耗，我们发现在低电场下，即在单光子极限下，损耗本质上是两能级系统，并且与 Al 电容值相关，而不是与 Al 电感相关。在高电场极限下，剩余损耗与 Al 面积乘以其电感的乘积线性相关，并且可能是由于杂散红外辐射产生的准粒子所致。在高温下，额外损耗与电感中的 Al 量相关，并且与功率无关的 TiN-Al 界面损耗项随着温度降低呈指数下降。在 50 mK 基础温度下，TiN-Al 界面损失非常小。
We present a method to systematically locate and extract capacitive and inductive losses in superconducting resonators at microwave frequencies by use of mixed-material, lumped element devices. In these devices, ultra-low loss titanium nitride was progressively replaced with aluminum in the inter-digitated capacitor and meandered inductor elements. By measuring the power dependent loss at 50 mK as the Al/TiN fraction in each element is increased, we find that at low electric field, i.e., in the single photon limit, the loss is two level system in nature and is correlated with the amount of Al capacitance rather than the Al inductance. In the high electric field limit, the remaining loss is linearly related to the product of the Al area times its inductance and is likely due to quasiparticles generated by stray IR radiation. At elevated temperature, additional loss is correlated with the amount of Al in the inductance, with a power independent TiN-Al interface loss term that exponentially decreases as the temperature is reduced. The TiN-Al interface loss is vanishingly small at the 50 mK base temperature.