Millimeter-Wave Four-Wave Mixing via Kinetic Inductance for Quantum Devices

TL;DR

This paper demonstrates millimeter-wave four-wave mixing using kinetic inductance in superconducting niobium nitride resonators, enabling nonlinear quantum devices at temperatures above 1 K with promising efficiency and performance.

Contribution

It introduces a novel approach to millimeter-wave four-wave mixing utilizing kinetic inductance in niobium nitride films, advancing superconducting quantum device technology.

Findings

Achieved four-wave mixing at ~100 GHz in niobium nitride resonators.

Measured quality factors up to 6×10^4 limited by two-level systems.

Demonstrated degenerate parametric conversion with +16 dB efficiency.

Abstract

Millimeter-wave superconducting devices offer a platform for quantum experiments at temperatures above 1 K, and new avenues for studying light-matter interactions in the strong coupling regime. Using the intrinsic nonlinearity associated with kinetic inductance of thin film materials, we realize four-wave mixing at millimeter-wave frequencies, demonstrating a key component for superconducting quantum systems. We report on the performance of niobium nitride resonators around 100 GHz, patterned on thin (20-50 nm) films grown by atomic layer deposition, with sheet inductances up to 212 pH/square and critical temperatures up to 13.9 K. For films thicker than 20 nm, we measure quality factors from $1$-$6\times 10^4$, likely limited by two-level systems. Finally we measure degenerate parametric conversion for a 95 GHz device with a forward efficiency up to +16 dB, paving the way for the development of nonlinear quantum devices at millimeter-wave frequencies.