Achiral crystal reveals Raman optical activity through ferroaxial order

Raman optical activity, long thought to require chiral molecules or magnetic order, has been demonstrated in an achiral, nonmagnetic crystal by researchers at the Institute of Science Tokyo. The effect arises through ferroaxial order, a coordinated rotation of atoms within the lattice, and is detected using circularly polarized Raman spectroscopy. The findings show that optically inactive materials can also display chirality-like optical responses and expand the scope of optical techniques for discovering new materials.