A waveguide-based resonant-phase-matching Josephson traveling-wave parametric amplifier with efficient phase correction

Josephson Traveling-Wave Parametric Amplifiers (JTWPAs) play a crucial role in scaling quantum processors, offering the wide bandwidth and dynamic range necessary for multiplexed qubit readout [1]. While resonant-phase-matching (RPM) techniques implemented using phase-matching lumped-element resonators have shown promise in delivering high-performance JTWPAs [2], existing approaches face significant challenges, particularly in achieving consistent resonator frequencies across a device. Although waveguide resonators can be used as alternatives, their large footprints limit their density and, consequently, their capabilities for efficient phase correction [3].



We propose a new method to couple the JTWPA line to phase-matching resonators, which can address the limitations of conventional implementations using lumped-element and waveguide resonators. This method preserves the efficient phase matching of lumped-element designs while making use of the good frequency homogeneity of waveguide resonators. This also mitigates issues such as coupling to higher-frequency modes, and reduces the total number of resonators required for a given JTWPA length. We show how this architecture can simplify device fabrication without compromising performance, informed by preliminary experimental results.



[1] J. Heinsoo et al., Phys. Rev. Applied 10, 034040 (2018)

[2] C. Macklin et al., Science 350, 307-310 (2015)

[3] T. C. White, Appl. Phys. Lett. 106, 242601 (2015)