The most interesting superconducting materials are also the most fragile, and for years that fragility has kept them confined to the lab. Atom-thin superconductors, sheets of material just one or a few atoms deep, can carry current without resistance while storing far more energy per unit area than their bulk counterparts, which makes them attractive building blocks for compact quantum devices. The problem is that they oxidize almost immediately on contact with air, so researchers could only work with tiny flakes peeled off larger crystals, and any attempt to build a practical circuit out of them failed before it began. A team at MIT and collaborating institutions has now found a way around that constraint, and the results, published in Nature on August 5, point toward a genuinely manufacturable route to air-stable 2D superconductors.
The material in question is niobium diselenide, a monolayer superconductor with a striking internal structure: a single closely packed plane of niobium atoms sandwiched between planes of selenium atoms. Its appeal lies in kinetic inductance, a measure of how much inductive energy a material can pack into a small footprint. In conventional quantum circuits, engineers achieve large kinetic inductance by chaining together arrays of Josephson junctions, which consumes space and complexity. A thin film with intrinsically high kinetic inductance could replace those arrays with a sliver of material, shrinking circuits dramatically. The catch: niobium diselenide degrades in air so quickly that reliable device fabrication at any useful scale had been impossible, and the standard fix, growing the material first and capping it with a protective layer afterward, failed because oxidation began before the cap could be applied.
The MIT approach inverts that order. The researchers deposit a layer of graphene, another atomically thin material, on a silicon dioxide substrate first, then grow the niobium diselenide underneath it, in the narrow gap between the graphene and the substrate. That gap is less than a nanometer wide, a consequence of the weak adhesion between the two materials, and the superconductor grows only within it. The substrate traps the chemical precursors long enough for crystals to form, while the graphene above allows them to travel and merge into one unbroken layer. The graphene thus does double duty: it templates the growth and, because the material is already encapsulated, it protects the finished film from the atmosphere. The same approach works with hexagonal boron nitride as the capping layer, and the mechanism, which the researchers call encapsulation epitaxy, extends beyond niobium diselenide to a broader family of monolayer quantum materials.
The proof of concept goes beyond a pretty film. The team produced a smooth and continuous niobium diselenide film more than 2.54 cm (1 inch) wide, then integrated it into a working superconducting microwave circuit. Connecting an atom-thin film to electrodes hundreds of nanometers thick required an oxidation-free transfer technique and careful side-wall etching in a vacuum chamber. After that clean-room processing, the material held onto its superconducting properties and its high kinetic inductance. In the long run, the group says, this could enable miniaturized superconducting quantum computing hardware and ultra-sensitive quantum sensors for telecommunications or cosmology.
What matters most about this result is not the physics, since monolayer superconductivity in niobium diselenide has been known for years, but the manufacturing story. Wafer-scale growth with a built-in protective layer is the difference between a material that exists in principle and one that can be fed into a fabrication line. The hidden constraint remains the other side of superconductivity: these devices still require cryogenic operation, so the payoff is in denser, more capable quantum circuits rather than room-temperature computing. Still, the work closes a stubborn gap between an atomically thin curiosity and an engineering material, and it gives quantum hardware developers a reason to revisit a family of materials they had written off as too delicate to use.
Sources: Researchers make air-stable, ultrathin superconductors, for more scalable quantum devices (MIT News, Aug 5, 2026); Scientists develop ultrathin superconductors that can help build more compact quantum devices (Interesting Engineering, Aug 6, 2026); Air-stable, ultrathin superconductors developed for more scalable quantum devices (Phys.org, Aug 5, 2026); MIT Creates Air-Stable Ultrathin Superconductors for Quantum Devices (TechExplorist, Aug 2026); Encapsulation epitaxy study (Nature, Aug 5, 2026)