Noise in Traveling-Wave Parametric Amplifiers

We discuss experimental results of noise in a broadband traveling-wave parametric amplifier (TWPA) utilizing a four-wave mixing process. The TWPA measured utilizes a phase matching approach which does not require dispersion engineering and is based on the Kerr reversal technique [1]. We have fabricated and measured two nominally identical TWPAs with different dielectrics of the grounding capacitors, one with higher loss SiO₂ dielectric and the second with low loss SiNx dielectric. Noise measurements of the two TWPAs show amplifier added noise near the quantum limit and to be primarily dominated by higher parametric mixing products. These results agree with numerical simulations which will be discussed.

[1] M. Bell and A. Samolov, Phys. Rev. Applied 4, 024014 (2015).