JPA with Improved bandwidth and saturation of power, Part II: Experiment

Josephson parametric amplifiers (JPAs) have become crucial components of superconducting qubit measurements to overcome the low signal to noise ratio in the dispersive readout scheme and enabling single-shot readout. To enable multiplexing of qubit readout along a single line, we have designed broadband JPAs with higher saturation power. We develop a measurement approach to optimize JPA performance using a pulsed measurement scheme to carefully select operating parameters such as DC bias, pump frequency and pump power. The pulsed bring-up is enabled by software defined radios for scalable characterization. We describe the characterization and performance of these JPAs and discuss implications on qubit measurement fidelity and multiplexing.