On-Chip Resonator for Nonlinear Kinetic Inductance Characterisation and Future Spectrometry Applications

TL;DR

This paper develops a tunable superconducting on-chip resonator using aluminium's non-linear kinetic inductance, studying its properties and potential for spectrometry and amplification applications.

Contribution

It introduces a method to characterize non-linear kinetic inductance in aluminium films and explores its application in future spectrometry and parametric amplification.

Findings

Resistivity, critical current, and critical temperature vary with film stoichiometry.

Microwave measurements align with a non-linear kinetic inductance model.

Potential use in parametric amplifiers is discussed.

Abstract

This work focuses on the development and demonstration of tunable superconducting on-chip resonator, leveraging the intrinsic current-dependent non-linear kinetic inductance of superconducting aluminium, and investigating the effect of oxygen content. Thin films are deposited using standard metal evaporation. We present results from a comprehensive study based on a series of evaporated Al thin films. This research aims to inform and constrain optimisation strategies for the design of mm-wave on-chip spectrometers, particularly regarding yield, resolution, and efficiency. By systematically varying film stoichiometry, we use a series of DC measurements to extract fundamental film properties such as resistivity, critical current and critical temperature. Furthermore, we employ low-loss DC-coupled microwave resonators to characterise both their microwave properties and the non-linear kinetic inductance, comparing these findings to a determined non-linear kinetic model. Finally, we discuss the possibility of usage in a parametric amplifier.