Researchers from Radboud University managed to optically switch individual domains into a definite magnetic state in the insulator Sm1/2Pr1/2FeO3. With short pulses of circularly polarized laser light, they flipped the magnetization of a single magnetic domain within ?5ps.

The team managed to achieve this by taking advantage of the interaction between light of a certain helicity and a spin reorientation transition unique to the material they studied. This is an important step for the complete light control of magnetic domains in a variety of magnets, and highlights an important light-matter interaction in magnets.