AI 中文总结
该研究证实动能感应行波参量放大器（KTWPA）可在多特斯拉场中稳定运行，在近平行于场的取向、0.25-0.5T场强下可获峰值增益，增益超20dB，有望拓展强场下量子极限射频测量的应用
AI 中文摘要
低温参量放大器被用于放大射频信号，服务于基础科学与应用科学的诸多应用场景。约瑟夫森参量放大器和约瑟夫森行波参量放大器均被用作第一级放大器，使读出链能够在量子极限的几个量子内运行。然而，这些器件对磁场高度敏感，其临界电流会因夫琅禾费效应而受到抑制，因此需要大量无场区。在暗物质轴子搜索实验中，轴子会在强磁场作用下转化为可探测的微波光子，这就要求放大器能够在这类环境附近可靠运行。动能感应行波参量放大器（KTWPAs）可能是这类应用的理想候选，因为其整个结构所用材料具有高临界磁场。本通讯中，我们证明KTWPAs在多次暴露于多特斯拉场的情况下，仍可在多吉赫兹带宽上提供高增益（>20dB）。此外，我们研究了这些器件在恶劣条件下的运行特性，将其作为总场强、器件在磁场中的取向、施加的偏置电流以及泵浦功率和频率的函数。在此过程中，我们发现，在垂直于0.02T磁场取向的器件中，KTWPA增益会消失；但当器件平面接近平行于磁场取向时，在超过1T的磁场中可实现>10dB的增益，且在施加0.25T至0.5T的磁场时可获得峰值增益。我们期望KTWPAs将扩大在特斯拉级磁场环境下量子极限射频测量的可及性。
英文摘要
Cryogenic parametric amplifiers are used to amplify radio-frequency signals for a range of applications in basic and applied science. Both Josephson Parametric Amplifiers and Josephson Traveling-Wave Parametric Amplifiers have been used as first-stage amplifiers enabling readout chains operating within a few quanta of the quantum limit. However, these devices are highly sensitive to magnetic fields, having critical current suppressed by the Fraunhofer effect, requiring substantial field-free zones. In a dark matter axion search experiment, axions convert to detectable microwave photons in the presence of a strong magnetic field, necessitating amplifiers that can reliably operate close to these environments. Kinetic-inductance Traveling-Wave Parametric Amplifiers (KTWPAs) may be the ideal candidate for this type of application having high critical magnetic field of the materials used throughout their construction. In this letter we demonstrate that KTWPAs can provide high gain (>20dB) over a multi-GHz bandwidth in spite of from multiple exposures to multi-Tesla fields. Further, we explore operational characteristics of these devices under harsh conditions as a function of overall field strength, device orientation within the field, applied bias current, and pump power & frequency. In so doing, we find KTWPA gain vanishes in devices oriented perpendicularly to a field of 0.02T, but gain values >10dB are achievable in fields over 1T when oriented near~parallel to the device plane, with peak gain achieved with an applied 0.25T to 0.5T field. It is our expectation that KTWPAs will expand the accessibility of quantum-limited RF measurements in the presence of Tesla-scale fields.
Comments10 pages, 5 figures, supplementary information included as appendix
