Traveling Wave Parametric Amplifier based on a chain of Coupled Asymmetric SQUIDs

摘要

A traveling wave parametric amplifier (TWPA) composed of a transmission linemade up of a chain of coupled asymmetric superconducting quantum interferencedevices (SQUIDs) is proposed. The unique nature of this transmission line isthat its nonlinearity can be tuned with an external magnetic flux and can evenchange sign. This feature of the transmission line can be used to perform phasematching in a degenerate four-wave mixing process which can be utilized forparametric amplification of a weak signal in the presence of a strong pump.Numerical simulations of the TWPA design have shown that with tuning, phasematching can be achieved and an exponential gain as a function of thetransmission line length can be realized. The flexibility of the proposeddesign can realize: compact TWPAs with less than 211 unit cells, signal gainsgreater than 20 dB, 3 dB bandwidth greater than 5.4 GHz, and saturation powersup to -98 dBm. This amplifier design is well suited for multiplexed readout ofquantum circuits or astronomical detectors in a compact configuration which canfoster on-chip implementations.