Flux-driven Josephson traveling-wave parametric amplifier

TL;DR

This paper introduces a flux-driven traveling-wave parametric amplifier using a SQUID array, achieving wide bandwidth, adjustable phase matching, and overcoming pump depletion, suitable for quantum information applications.

Contribution

It presents a novel flux-driven design for a traveling-wave parametric amplifier with adjustable phase velocity and improved gain characteristics.

Findings

Achieves large gain over a wide frequency range

Demonstrates adjustable phase velocity for phase matching

Overcomes pump depletion problem

Abstract

We have developed a concept for a traveling-wave parametric amplifier driven by a magnetic flux wave. The circuit consists of a serial array of symmetric dc SQUIDs coupled inductively to a separate superconducting LC transmission line carrying the pump microwave; thereby the signal and pump are applied to different ports. The proposed three-wave-mixing amplifier includes, firstly, an adjustable phase velocity of the signal (idler) wave and hence good phase matching yielding large gain in a wide frequency range and, secondly, overcoming of the pump depletion problem. The experimental parameters and characteristics of this amplifier have been evaluated and show promise for applications in quantum-information single-photon circuits.