Taige Wang

Layers of a thin material rotated relative to each other resemble stacked grids. Where the lines intersect, a new pattern emerges — a moiré. In this pattern, electrons move differently than in a regular crystal and can form unexpected states. In the new study, researchers took two layers of molybdenum telluride and twisted them by 4.8 degrees.

Electrons in a solid usually either run freely (metal) or are locked in place (insulator). But sometimes strong mutual repulsion locks them into a halfway state: charges stand still, while spins, tiny magnetic arrows, continue to live their own life. This is called a Mott insulator.