fragile topology

Misaligned layers of graphene seem to exhibit a phenomenon known as fragile topology. (Juliette Halsey for Nature)

Almost every solid might be topological ‘Fragile topology’ is a newly discovered type of topological behaviour — a group of quantum phenomena that is rapidly becoming essential for understanding the properties of solid matter. In topological materials, some electrons share collective quantum states that contribute to exotic behaviour such as superconductivity. Fragile topology — only now being hinted at in real-world experiments — has exploded onto the scene because it seems to be everywhere: it might occur in almost all crystalline solids. Nature | 6 min read