Researchers map tiny twists in magic-angle graphene

In 2018, MIT scientists discovered that when two sheets of graphene are stacked together at a slightly offset "magic" angle, the new "twisted" graphene structure can become either an insulator or a superconductor. Now, the MIT scientists report that they and others have imaged and mapped an entire twisted graphene structure for the first time at a resolution fine enough that they are able to see slight variations in the local twist angle across the entire structure. The scientists also reported creating a new twisted graphene structure with not two, but four layers of graphene. They observed that the new four-layer magic-angle structure is more sensitive to certain electric and magnetic fields compared to its two-layer predecessor.