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arXiv · 2508.03873

Microwave characterization of superconducting coplanar resonators made out of granular aluminium

Kelvin J. Ramos·Ivana Curci·Erick Potosí·Ignacio Lobato·Leonardo Salazar Alarcón·Hernán Pastoriza·Leandro Tosi
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Abstract

We have designed, fabricated and characterized microwave resonators made out of thin films of granular aluminium (grAl) with different oxygen content. We extract the contribution of the large kinetic-inductance of this disordered superconductor from the frequency shift of the resonators as a function of temperature, and discuss the correlation with the resistivity of the films. At low temperatures, measurements of the internal quality factor as a function of microwave power indicate the presence of two-level systems, which are inherent to the growth process of the granular aluminium. The characterization methods presented here may be useful for the design of MKIDs, high-impedance resonators and superinductors.

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Kelvin J. Ramos, Ivana Curci, Erick Potosí, Ignacio Lobato, Leonardo Salazar Alarcón, Hernán Pastoriza, Leandro Tosi. 2025-08-05. Microwave characterization of superconducting coplanar resonators made out of granular aluminium. https://arxiv.org/abs/2508.03873

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