DC-operated Josephson junction arrays as a cryogenic on-chip microwave measurement platform

TL;DR

This paper demonstrates that DC-biased Josephson junction arrays can serve as on-chip microwave sources and detectors in cryogenic environments, potentially replacing bulky RF cabling for quantum measurements.

Contribution

It introduces a novel, fully DC-operated cryogenic on-chip microwave measurement platform using Josephson junction arrays capable of emission and detection.

Findings

JJAs can emit signals in the C-band and beyond.

Device parameters influence RF source behavior.

JJAs effectively detect microwave radiation.

Abstract

Providing radio frequency (RF) signals to circuits working in cryogenic conditions requires bulky and expensive transmission cabling interfacing specialized RF electronics anchored at room temperature. Superconducting Josephson junction arrays (JJAs) can change this paradigm by placing the RF source and detector inside the chip. In this work, we demonstrate that DC-biased JJAs can emit signals in the C-band frequency spectrum and beyond. We fabricate reproducible JJAs comprised of amorphous MoGe or NbTiN superconducting islands and metallic Au weak links. Temperature, magnetic fields, applied currents, and device design are explored to control the operation of the RF sources, while we also identify important features that affect the ideal source behavior. Combined with the proven ability of these JJAs to detect microwave radiation, these sources allow us to propose a fully DC-operated cryogenic on-chip measurement platform that is a viable alternative to the high-frequency circuitry currently required for several quantum applications.