Dzyaloshinskii-Moriya interaction in synthetic antiferromagnets with spatially alternating stress

Dzyaloshinskii-Moriya (DM) interaction is a source of chiral magnetic physics, and it manifests microstructural symmetry which could link to exotic magnetic and electronic properties such as altermagnetism. For a new paradigm in magnetism and spintronics, it is crucial to have control on the DM interaction as well as ordering of the DM vectors which characterize the DM interaction. In the presentation, we discuss a strong interlayer DM interaction emerged in Co/Ru magnetic superlattices whose structural symmetry is unambiguously broken by alternating mechanical strains developed using the unprecedented technique of our stress mechanism. Moreover, theoretical analyses reveal that our magnetic superlattices host a staggered order of the DM vectors. Our results indicate that the spatially varying strains with our breakthrough technique are quite effective in breaking the symmetry of the system and prove that it can control the DM interaction strength as well as the DM vector order.