Scientific Achievement
Using circularly polarized light, we achieve optical control of an antiferromagnet (AFM) for the first time. This phenomenon arises from the optical magneto-electric coupling.
Significance and Impact
New methods are needed to manipulate AFM order, which are immune to perturbing magnetic fields. Our discovery paves the way for AFM opto-spintronics. In topological AFM Axion insulators, our work opens the door for optical writing of dissipationless circuits formed by topological edge states at domain walls.
Research Details
- We detect and manipulate the AFM order using circularly polarized light in 2D even-layer MnBi2Te4 (an Axion insulator).
- We have discovered a novel type of circular dichroism proportional to the AFM order, which only appears in reflection but is absent in transmission.
- Utilizing two light beams with opposite helicity, we achieve optical creation of AFM domain walls.
J.-X. Qiu,… S.-Y. Xu, Nat. Mater. 22, 583 (2023). https://www.nature.com/articles/s41563-023-01493-5