A graphene layer lets an ultrathin superconductor grow uniformly while protecting it from oxidation outside controlled environments.<\/p>\n
MIT researchers have developed an ultrathin superconductor<\/a> that can be produced over large areas and remain stable in air, potentially enabling smaller and more scalable quantum devices.<\/p>\n The material, niobium diselenide, is only around one nanometre thick. Although it has promising superconducting properties, it typically oxidises and degrades almost immediately upon exposure to air.<\/p>\n Researchers addressed the problem by placing graphene on a silicon dioxide substrate before growing the superconductor<\/a>. Chemical precursors enter the narrow gap between the layers, where the niobium diselenide forms beneath the graphene.<\/p>\n The graphene protects the material from oxidation while guiding it into a smooth, continuous monolayer. Using the technique, the team produced a layer more than an inch across, rather than the tiny flakes typically obtained through conventional methods.<\/p>\n Researchers then developed an oxidation-free transfer process and integrated the material into a superconducting microwave circuit. It retained its superconducting behaviour after fabrication and exhibited high kinetic inductance.<\/p>\n High kinetic inductance allows substantial inductive energy to be stored within a small area. Quantum circuits currently achieve similar effects using arrays of Josephson junctions, which require considerably more space.<\/p>\n Replacing such arrays with a small piece of ultrathin superconducting material could help miniaturise superconducting quantum hardware and technologies, including highly sensitive quantum detectors.<\/p>\n The growth technique is not limited to niobium diselenide. Researchers demonstrated that it could be extended to other atomically thin quantum materials with different potentially useful properties.<\/p>\n