Noise Characterization of Impedance-Matched Broadband Josephson Parametric Amplifier

Josephson parametric amplifiers (JPAs) are essential tools in experiments involving superconducting quantum circuits due to their quantum-limited performance. However, traditional JPAs suffer from restricted gain-bandwidth products and low compression powers, which prohibits their applications in many modern experiments with superconducting quantum circuits. Here, we present the design and characterization measurements of a broadband JPA that integrates an on-chip impedance matching circuit using a fully planar geometry. Gain measurements reveal a gain-bandwidth enhancement of nearly two orders of magnitude, as compared to conventional JPAs. We investigate the added amplification noise of our broadband JPA in order to highlight its quantum-limited performance and compare various approaches to evaluate noise in broadband superconducting amplifiers. Our results demonstrate the applicability and robustness of impedance-matched JPAs for various quantum applications, such as the broadband squeezing generation and fast qubit readout.