Three-wave mixing traveling-wave parametric amplifier with periodic variation of the circuit parameters*

We report the implementation of a traveling-wave parametric amplifier (TWPA) with magnetically biased SNAIL loops that provide three-wave mixing (3WM). We use the intrinsic dispersion of the chain for phase matching but suppress the generation of the higher harmonics of the pump, the signal, and the idler by adding dispersive features. We achieve this by means of periodic loading to create a stopband at the second harmonic of the pump. With this design, we obtain a gain of up to 20 dB in a TWPA with only 440 LC units, a 3-dB bandwidth of about 1GHz with added noise of less than one photon. Moreover, the stopband allows for adjusting the frequency of the pump over the GHz range [1].

[1] A. Fadavi Roudsari, et. al, arXiv:2209.07551.