论文标题
Al和Ti超导拖网波参数放大器中的非线性机制
Nonlinear mechanisms in Al and Ti superconducting travelling-wave parametric amplifiers
论文作者
论文摘要
行驶波参数放大器（TWPA）操作背后的基本非线性机制对于确定其在增加噪声，最大增益和带宽方面的性能很重要。我们描述了一种表征超导材料的潜在非线性的方法，其耗散性比率和基础显微镜过程的响应时间。我们描述并计算出均衡的非线性均衡的不同行为，该行为具有较低的耗散和快速响应时间，而非平衡加热非线性具有较高的耗散和缓慢的响应时间。我们已经根据AL和TI制造了TWPA，并使用我们的分析来表征它们的非线性。对于AL和TI，测得的耗散反应比和响应时间在定量上与非平衡加热非线性的预测相似。我们能够获得超过20 dB的峰值功率增益，尽管仅在几千摩尔兹省的狭窄带宽上。我们表征潜在的非线性的方法也可以在理解和设计其他超导非线性设备的方法中有用，例如参数上的上传感器，动力电感傅立叶傅立叶变换光谱仪和谐振器参数放大器。
The underlying nonlinear mechanisms behind the operation of travelling-wave parametric amplifiers (TWPAs) are important in determining their performance in terms of added noise, maximum gain, and bandwidth. We describe a method of characterising the underlying nonlinearity of a superconducting material in terms of its dissipative-reactive ratio and the response time of the underlying microscopic processes. We describe and calculate the different behaviour arising from the equilibrium supercurrent nonlinearity, which has low dissipation and fast response time, and the non-equilibrium heating nonlinearity, which has high dissipation and slow response time. We have fabricated TWPAs based on Al and Ti, and characterised their nonlinearities using our analysis. For both Al and Ti, the measured dissipative-reactive ratios and response times are quantitatively similar to predictions for the non-equilibrium heating nonlinearity. We were able to obtain more than 20 dB of peak power gain, although only over a narrow bandwidth of a few kilohertz. Our method of characterising the underlying nonlinearities could also be useful in the understanding and design of other superconducting nonlinear devices such as parametric up-converters, kinetic inductance Fourier transform spectrometers, and resonator parametric amplifiers.
