We develop a concept of the traveling-wave Josephson parametric amplifier exploiting quadratic nonlinearity of a serial array of one-junction superconducting quantum interference devices (SQUIDs) embedded in a superconducting transmission line. The external magnetic flux applied to the SQUIDs makes it possible to efficiently control the shape of their current-phase relation and, hence, the balance between quadratic and cubic (Kerr-like) nonlinearities. This property allows us to operate in the favorable three-wave-mixing mode with a minimal phase mismatch, an exponential dependence of the power gain on number of sections $N$, a large bandwidth, a high dynamic range, and substantially separated signal (${\omega }_s$) and pump (${\omega }_p$) frequencies obeying the relation ${\omega }_s+{\omega }_i={\omega }_p$, where ${\omega }_i$ is the idler frequency. An estimation of the amplifier characteristics with typical experimental parameters, a pump frequency of 12 GHz, and $N=300$ yields a flat gain of 20 dB in the bandwidth of 5.6 GHz.

• Received 26 February 2016

DOI:https://doi.org/10.1103/PhysRevApplied.6.034006