Unlocking magnetic ferro-rotational functionalities.

Ferro-rotation (FR) phenomena-arising from intrinsic crystallographic rotational distortions-have only recently gained significant attention, despite the long-known presence of FR distortions in various compounds. Such phenomena include multiferroicity linked to helical spin order and electric field-induced optical activity. However, the broader relationship between FR and magnetic ordering remains largely unexplored and poorly understood. This study delves into the interplay between magnetic order and FR identifies potential materials capable of hosting magnetic FR and explores the interaction between magnetic FR and external stimuli. Our analysis reveals that out of the 122 magnetic point groups, 43 of them exhibit magnetic FR. Materials belonging to these magnetic point groups hold promise for demonstrating magnetic order-induced FR. Notably, the combination of parity/time reversal-odd antiferromagnetic order and FR can lead to the emergence of directionally nonreciprocal spin waves, as exemplified in MnTiO3. Moreover, our investigation uncovers novel magnetic order-induced switchable chirality, when magnetic FR objects are exposed to external electric fields or temperature gradients. Overall, this research elucidates the intricate relationship between FR, magnetic order, and external perturbations, revealing the untapped potential and functionalities of magnetic FR materials.