Mesostructured Metal Superconductors via Block Copolymer Nanocomposites: Quantum Metamaterials from Soft Matter*

Three-dimensionally mesostructured superconductors have unique properties compared to thin film or bulk analogues, but their investigation has been limited by the lack of facile synthesis methods. Though largely unexplored in this application, block copolymers (BCPs) can serve as structure-directing agents to tune material architectures and, by extension, properties over scales on the order of characteristic lengths in superconductors (10s of nm). Hybrid BCP-inorganic self-assembly provides a route to mesostructured NbN superconductors, but complex materials chemistry prevents comparison with bulk equivalents. In recent work we demonstrate a versatile approach to mesoscale ordered metal superconductors via self-assembly of BCP nanocomposites. Results indicate quantum metamaterials behavior, with evidence that properties such as the transition temperature, coherence length, and critical field change substantially in a 3D periodic mesostructure (e.g., the bicontinuous double gyroid). Future work will investigate emergent phenomena such as angle-dependent magnetization behavior, and expansion of our technique to other metals could lead to novel photonic, electronic, and/or catalytic properties.