JPA with Improved bandwidth and saturation of power, Part I: Design

An attractive strategy for scaling up superconducting qubits is to multiplex qubit readout onto a single line. This places a constraint on the parametric amplifier which amplifies the readout signal to have increased bandwidth and saturation power capabilities so that multiple readout pulses can be handled. Here, we present the design approach used at Rigetti to realize both broadband JPA's and JPA's with higher saturation power. For increasing bandwidth we analyze an optimization procedure to realize impedance matching networks given a desired bandwidth. We present the performance of the JPAs from our numerical solutions