A15 superconductors are distinguished by their high critical temperatures, magnetic fields, and current-carrying capabilities. Among them, Nb3Al is of particular interest for superconducting quantum circuits as a means to extend device operating temperatures, provided that its electrodynamic properties are well understood. Here, we report on the synthesis of Nb3Al thin films by magnetron co-sputtering followed by rapid thermal processing, yielding superconducting transition temperatures above 16~K. Microwire devices patterned from these films exhibit a coherence length of 3.2nm and superfluid densities as low as 1.1×1026m−3, suggesting that Nb3Al may enable high kinetic inductance in thinner films. Coplanar waveguide resonators fabricated on Nb3Al demonstrate single-photon internal quality factors up to 2.26×105. These results establish Nb3Al as a promising material platform for the development of superconducting quantum circuits operating at elevated temperatures, contingent on appropriate control of interfacial chemistry and surface morphology.
@article{arxiv.2512.05396,
title = {An evaluation of A15 Nb3Al superconducting thin films for application in quantum circuits},
author = {Joseph Falvo and Brooke Henry and Bernardo Langa and Rohit Pant and Ashish Alexander and Jason Dong and Kasra Sardashti},
journal= {arXiv preprint arXiv:2512.05396},
year = {2025}
}