Hofstadter Butterfly Fractal in Graphene Moiré Superlattices (image) Columbia University Share Print E-Mail Caption This is an artistic image illustration of a butterfly departing from a graphene moiré pattern formed on the top of an atomically thin boron nitride substrate. Electron energy in such a graphene moiré structure exhibits the butterfly like a self-recursive fractal quantum spectrum. Credit Columbia Engineering Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.