Ultrathin materials made of a single layer of atoms
have riveted scientists’ attention since the discovery of the first
such material—graphene—about 17 years ago. Among other advances
since then, researchers including those from a pioneering lab at
MIT have found that stacking individual sheets of the 2D materials,
and sometimes twisting them at a slight angle to each other, can
give them new properties, from superconductivity to
magnetism.