A microwave amplifier combining noise performances as close as possible to the quantum limit with large bandwidth and high saturation power is highly desirable for many solid state quantum technologies. Here we introduce a new Traveling Wave Parametric Amplifier based on Superconducting QUantum Interference Devices. It displays a bandwidth, a saturation (1dB compression) point and added noise near the quantum limit. Compared to previous state-of-the-art, it is an order of magnitude more compact, its characteristic impedance is in-situ tunable and its fabrication process requires only two lithography steps. The key is the engineering of a gap in the dispersion relation of the transmission line. This is obtained using a periodic modulation of the SQUID size, similarly to what is done with photonic crystals. Moreover, we provide a new theoretical treatment to describe the non-trivial interplay between non-linearity and such periodicity. Our approach provides a path to co-integration with other quantum devices such as qubits given the low footprint and easy fabrication of our amplifier.

中文翻译：

---

光子晶体约瑟夫森行波参数放大器

对于许多固态量子技术而言，非常需要将噪声性能尽可能接近量子极限并具有大带宽和高饱和功率的微波放大器。在这里，我们介绍一种基于超导量子干扰设备的新型行波参量放大器。它显示了一个带宽，一个饱和点（1dB压缩点）和接近量子极限的附加噪声。与以前的最新技术相比，它的结构紧凑了一个数量级，其特性阻抗是可现场调节的，其制造过程仅需要两个光刻步骤。关键是传输线的色散关系中存在间隙。这是使用SQUID大小的周期性调制来实现的，这与光子晶体类似。此外，我们提供了一种新的理论方法来描述非线性与这种周期性之间的非平凡相互作用。鉴于我们的放大器占地面积小且易于制造，我们的方法提供了与其他量子设备（例如量子位）共集成的途径。