Researchers make air-stable, ultrathin superconductors, for more scalable quantum devices

Researchers at MIT and other institutions have developed a method to create ultrathin superconductors that remain stable in air, paving the way for more scalable quantum devices. Superconducting materials, which exhibit zero electrical resistance, hold promise for miniaturizing quantum computing hardware and other technologies. However, existing ultrathin superconductors degrade rapidly in air, limiting their practical applications.

The team discovered a technique to "grow" niobium diselenide, an ultrathin superconducting material, in a gap between graphene and a silicon dioxide substrate. The graphene layer protects the superconductor from oxidation while guiding its uniform growth over a large wafer-scale area. This approach allows for the fabrication of a stable, air-stable superconductor on a larger scale compared to previous methods.

The researchers integrated the air-stable niobium diselenide into a superconducting microwave circuit, demonstrating that the material maintains its superconducting properties and exhibits high kinetic inductance. Kinetic inductance is crucial for many quantum devices, as it enables them to store inductive energy in a compact form. By replacing large arrays of Josephson junctions with a small piece of niobium diselenide film, the researchers aim to create more compact and efficient quantum circuits.

This breakthrough could lead to miniaturized superconducting quantum computing hardware and advanced technologies such as ultrasensitive quantum detectors for communications and cosmology. Co-lead author Xudong Sheldon Zheng notes that the new process opens up exciting opportunities for scientists to study and utilize ultrathin superconductors in practical applications.