Superconducting nitridized-aluminum thin films

We report the direct observation of superconductivity in nitridized-aluminum thin films. The
films are produced by sputtering deposition of aluminum in a controlled mixture of nitrogen
diluted in argon. The concentration of applied nitrogen directly determines the properties of the
superconducting thin films. We observe samples displaying critical temperatures up to
3.38 ± 0.01 K and resilience to in-plane magnetic fields well above 1 T, with good
reproducibility of the results. This work represents an unambiguous demonstration of tunable
superconductivity in aluminum-based nitridized thin films. Our results put forward nitridized
aluminum as a promising material to be employed in superconducting quantum circuits for
quantum technology applications.