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

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.