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

Researchers from MIT and other institutions have developed a method to produce air-stable, ultrathin superconductors, which could lead to more compact, scalable, and efficient quantum devices. Superconductors are materials that can conduct electricity without resistance, a crucial property for quantum devices. However, traditional superconductors degrade rapidly when exposed to air, making them difficult to study and manufacture.

The researchers grew the superconducting material, niobium diselenide, beneath a protective layer of graphene, an atomically thin carbon-based material. The graphene layer shields the fragile superconductor from oxidation, allowing it to grow in a smooth layer over a large wafer-scale area. This approach overcomes the challenges associated with traditional growth methods, which yield small flakes and struggle to achieve uniform monolayer thickness.

The air-stable superconductor was integrated into a superconducting microwave circuit, where it maintained its superconducting properties and exhibited high kinetic inductance. Kinetic inductance is a desirable trait in many quantum devices, as it allows for the storage of inductive energy in a small area. The researchers' breakthrough could enable the miniaturization of superconducting quantum computing hardware and the development of ultrasensitive quantum detectors for various applications, such as communications and cosmology.

Co-lead author Xudong Sheldon Zheng, an MIT graduate student, emphasized the potential impact of this discovery, stating that emerging superconductors with a monolayer thickness now have the opportunity to be studied, utilized, and applied in practical scenarios. The research findings were published in the journal Nature.