A comparative study of Josephson Traveling Wave Parametric Amplifiers

Several desirable features of Josephson Traveling Wave Parametric Amplifiers (JTWPAs),such as broadband gain with no fixed gain-bandwidth product, unilateral amplification, and large dynamic range, have led to their emergence as a standard modality for low-noise quantum signal processing in multi-qubit superconducting architectures. However, in the absence of a unified framework, study of J-TWPAs remains artisanal and restricted almost exclusively to designs based on right-handed (RH) Josephson transmission lines. In a recent work [1], we introduced a left-handed (LH) J-TWPA that has phase matching native to its operation, along with a unified J-TWPA landscape to inform optimal design and operation. In this talk, we will leverage this unified picture to present a detailed comparison between performance of realistic devices spanning LH and RH designs. To this end, we will present an analytical treatment for modeling linear response of J-TWPAs both in the classical and quantum regimes, while including the effect of non-idealities and practical imperfections. We will conclude with pointers provided by our investigations on prospects and strategies for J-TWPAs to achieve the longstanding challenge of broadband squeezing.