Manipulation of antiferromagnetic order with light

Optical detection and switching graphics.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).