Towards a SQUID-based Traveling Wave Parametric Amplifier

Superconducting Parametric Amplifiers are key to research fields involving microwave signals in the quantum regime, such as superconducting qubits or NEMs because of the large gain they provide and their noise performance. Large interaction time between a weak microwave signal, a strong coherent pump tone and a non-linear medium is required to obtain enough gain. Up to now, this was achieved by coupling the non-linear medium to a resonator. But this is also possible by using distributed non-linear media and working in transmission, thus overriding issues of limited bandwidth due to resonant cavities. When the medium is a Josephson junction, this new class of amplifier is called Josephson Traveling Wave Parametric Amplifier (J-TWPA) [1]. We will present our on-going effort to develop a SQUID-based TWPA. It will allow to tune in situ the characteristic impedance of the TWPA to have a perfect impedance match with the rest of the electronic setup, despite the uncertainty of the electrical properties of the device due to the fabrication process.

[1] C. Macklin et al., Science 350, 6258 (2015)