Near quantum limited Josephson traveling wave amplifiers I, Fabrication and characterization*

Efficient low noise amplification is a crucial component for any system dealing with low amplitude signals. Currently, Josephson parametric amplifiers(JPAs) can attain quantum limited amplification for microwave signals. However, JPAs based on resonant structures are limited to low bandwidth and saturation power. These limitations can be overcome using Josephson meta-materials forming traveling wave parametric amplifiers(TWPAs).

In part I, we will present in detail, our simplified aluminum-based two-step fabrication technique for TWPAs with low footprint[1], and discuss their linear characterization[2]. This technique paves the way for on-chip integration of broadband amplifiers with quantum devices.

In part II, we will present the performance of these amplifiers, exhibiting a large and near quantum limited gain over bandwidth larger than 2GHz; and conclude with a discussion on techniques for mitigating some of the limitations.


[1] L. Planat et al., arXiv:1907.10162
[2] L. Planat et al., arXiv:1907.10158