Hysteretic Flux Response and Nondegenerate Gain of Flux-Driven Josephson Parametric Amplifiers
Hysteretic Flux Response and Nondegenerate Gain of Flux-Driven Josephson Parametric Amplifiers
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DOI：
10.1103/physrevapplied.8.024012
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发表时间：
2017-08-17
影响因子：
4.6
通讯作者：
Gross, Rudolf
中科院分区：
文献类型：
--
作者：
Pogorzalek, Stefan;Fedorov, Kirill G.;Gross, Rudolf
约瑟夫森参量放大器（JPA）已成为超导电路量子科学技术的关键器件。特别是，它们可以用作量子限制放大器或压缩微波场源。在这里，我们报告了五个磁通驱动 JPA 的详细测量结果，显示了谐振频率对所施加磁通量的滞后依赖性。我们基于直流超导量子干涉装置的二维势图，通过数值模拟对测量的特性进行建模，提供非零筛选参数 beta(L) > 0 的 JPA 非线性，并证明数值结果与实验数据之间具有良好的一致性。此外，我们研究了不同 JPA 的非简并响应，并用我们的理论准确地描述了实验结果。
Josephson parametric amplifiers (JPAs) have become key devices in quantum science and technology with superconducting circuits. In particular, they can be utilized as quantum-limited amplifiers or as a source of squeezed microwave fields. Here, we report on the detailed measurements of five flux-driven JPAs exhibiting a hysteretic dependence of the resonant frequency on the applied magnetic flux. We model the measured characteristics by numerical simulations based on the two-dimensional potential landscape of the dc superconducting quantum interference devices, which provide the JPA nonlinearity for a nonzero screening parameter beta(L) > 0 and demonstrate excellent agreement between the numerical results and the experimental data. Furthermore, we study the nondegenerate response of different JPAs and accurately describe the experimental results with our theory.