Impedance-matched CPW high kinetic inductance parametric amplifier

The Kinetic Inductance Parametric Amplifier (KIPA) is a strong candidate for enhancing superconducting qubit signal readout and control due to its ability to provide low-noise, wideband, and significant gain in amplification. Compared to the Josephson Parametric Amplifier (JPA), the simplicity of fabrication and scaling, along with better error tolerance, have stimulated significant research interests in recent years. However, achieving a 50 Ohm characteristic impedance match presents a challenge due to the system's nonlinear kinetic inductance. Currently, KIPAs reported in literature employ roughly 10pH/square Kinetic Inductance (KI), which necessitates a longer engineered transmission line and, consequently, a larger chip size. Importantly, if the transmission line is not perfectly impedance-matched or the total length is very long, the reflections or power losses become a significant issue. In our work, we have successfully designed and fabricated a series of high KI parametric amplifiers with KI values ranging from 50pH/square to 100pH/square. Preliminary results indicate that the KIPA can achieve large signal gain on a 4.2cm length dispersion-engineered high KI parametric amplifier.