Once the heated magnet begins to cool, its electrons again order themselves into a synchronized spin, typically in a different direction. The researchers built their laser switchable magnet from two thin, but slightly twisted layers of the organic semiconductor molybdenum ditelluride. Their two-layer material allowed topological states to form—that is, quantum states that are permanently defined and cannot be altered by small local disturbances. Experiments revealed that the material’s electrons existed in tunable topological states that could be manipulated from insulating to conducting. Potential Uses for Laser Switching MagnetsPrevious research has achieved such laser-based switching in single electrons, but it has never been accomplished at the scale of entire ferromagnets.