论文标题
研究高Q NB谐振器中氧化物再生物引起的微波损失的研究
Investigation of microwave loss induced by oxide regrowth in high-Q Nb resonators
论文作者
论文摘要
最先进的超导量子设备的一致性主要受到两级系统缺陷的限制，这主要是在无定形接口层上。通过适当的表面处理从这些接口中减少微波损失是推动设备性能向前推动的关键。在这里，我们在用氢氟酸蚀刻去除天然氧化物后研究尼伯物的谐振剂。我们研究了暴露于环境环境后的表面氧化物引入的微波损失的重新出现。我们发现，量子设备中的损失减少了一个数量级，当设备在16分钟内接触到环境条件时，内部Q因子在单个光子状态下达到7 $ \ cdot $ 10 $^6 $。此外，我们观察到NB2O5是唯一在延长的Cabrera-mott生长模型之后的最初200小时内显着生长的氧化物。在这段时间，微波损失与NB $ _2 $ o $ _5 $厚度线性线性，并带有提取的损失切线tan $δ$ = 9.9 $ \ cdot $ 10 $^{ - 3} $。对于从超导Qubit，量子限制的放大器，微波动力电感检测器到单个光子检测器的设备，我们的发现特别感兴趣。
The coherence of state-of-the-art superconducting qubit devices is predominantly limited by two-level-system defects, found primarily at amorphous interface layers. Reducing microwave loss from these interfaces by proper surface treatments is key to push the device performance forward. Here, we study niobium resonators after removing the native oxides with a hydrofluoric acid etch. We investigate the reappearance of microwave losses introduced by surface oxides that grow after exposure to the ambient environment. We find that losses in quantum devices are reduced by an order of magnitude, with internal Q-factors reaching up to 7 $\cdot$ 10$^6$ in the single photon regime, when devices are exposed to ambient conditions for 16 min. Furthermore, we observe that Nb2O5 is the only surface oxide that grows significantly within the first 200 hours, following the extended Cabrera-Mott growth model. In this time, microwave losses scale linearly with the Nb$_2$O$_5$ thickness, with an extracted loss tangent tan$δ$ = 9.9 $\cdot$ 10$^{-3}$. Our findings are of particular interest for devices spanning from superconducting qubits, quantum-limited amplifiers, microwave kinetic inductance detectors to single photon detectors.
