Year: 2024
Type: article
Abstract: The quest to manipulate and understand superconductivity demands exploring diverse materials and unconventional behaviors. Here, we investigate the Berezinskii-Kosterlitz-Thouless (BKT) transition in ${\mathrm{ReN}}_{x}$ thin films, demonstrating their emergence as a compelling platform for studying this pivotal phenomenon. By systematically varying synthesis parameters, we achieve ${\mathrm{ReN}}_{x}$ films exhibiting a BKT transition comparable to what is known from ${\mathrm{NbN}}_{x}$ meander structure films. Detailed current-voltage measurements unlock the intrinsic parameters of the BKT transition, revealing the critical role of suppressed superconducting volume in pushing ${\mathrm{ReN}}_{x}$ towards the two-dimensional limit. Utilizing this two-dimensional electron system, we employ Beasley-Mooij-Orlando theory to extract the vortex unbinding transition temperature and superelectron density at the critical point. Further confirmation of the BKT transition is obtained through temperature-dependent resistivity, current-voltage, and magnetoresistance measurements. Our findings suggest that native disorder and inhomogeneity within ${\mathrm{ReN}}_{x}$ thin films act to suppress long-range coherence, ultimately driving the system towards the BKT regime. This work establishes ${\mathrm{ReN}}_{x}$ as a promising material for exploring BKT physics and paves the way for tailoring its properties for potential applications in superconducting devices.
Institutions: NTT (Japan), NTT Basic Research Laboratories
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4400948360