Silicides—alloys of silicon and metals long used in microelectronics—are now being explored again for quantum hardware. But their use faces a critical challenge: achieving phase purity, since some silicide phases are superconducting while others are not.

The study, published in Applied Physics Letters by NYU Tandon School of Engineering and Brookhaven National Laboratory, shows how substrate choice influences phase formation and interfacial stability in superconducting vanadium silicide films, providing design guidelines for improving material quality.

The team, led by NYU Tandon professor Davood Shahrjerdi, focused on vanadium silicide, a material that becomes superconducting (able to conduct electricity without resistance) when cooled below its transition temperature of 10 Kelvin, or about −263°C. Its relatively high superconducting transition temperature makes it attractive for quantum devices that operate above conventional millikelvin temperatures.