Faint far-infrared radiation drives a correlated insulator-to-metal transition in magic-angle graphene

One of the central ideas in modern physics is the phase transition—a sudden transformation of the state of a material. We encounter phase transitions throughout everyday life: water freezes into ice, wax melts in the warmth of a flame, and water vapor condenses into droplets on a cold window. In these familiar examples, the atoms themselves rearrange into a new structure, giving the material entirely different properties.