Berezinskii-Kosterlitz-Thouless transition in rhenium nitride films

We present a comprehensive study of the Berezinskii-Kosterlitz-Thouless (BKT) transition in ReN_x thin films. By systematically varying synthesis conditions, we achieved films exhibiting a BKT transition comparable to that observed in NbN_x, establishing ReN_x as a promising platform for exploring two-dimensional superconductivity.

Detailed characterization techniques, including current-voltage measurements and Beasley-Mooij-Orlando theory, allowed us to extract the intrinsic parameters of the BKT transition and elucidate the role of suppressed superconducting volume due to disorder and inhomogeneity in driving the system towards the two-dimensional limit. Additionally, temperature-dependent resistivity and magnetoresistance measurements provided further confirmation of the BKT transition.

Our findings suggest that native disorder and inhomogeneity within ReN_x films contribute to suppressing long-range coherence, ultimately driving the system into the BKT regime. These results pave the way for tailoring ReNx films for potential applications in superconducting devices.