Ultrafast Optically Induced Ferromagnetic State in an Elemental Antiferromagnet

We present evidence for an ultrafast optically induced ferromagnetic alignment of antiferromagnetic Mn in Co/Mn multilayers. We observe the transient ferromagnetic signal at the arrival of the pump pulse at the Mn L-3 resonance using x-ray magnetic circular dichroism in reflectivity. The timescale of the effect is comparable to the duration of the excitation and occurs before the magnetization in Co is quenched. Theoretical calculations point to the imbalanced population of Mn unoccupied states caused by the Co interface for the emergence of this transient ferromagnetic state.

Automated summary

The study provides evidence for an ultrafast optically induced ferromagnetic alignment of antiferromagnetic Mn in Co/Mn multilayers. The transient ferromagnetic signal is observed at the arrival of the pump pulse at the Mn L-3 resonance, indicating a timescale comparable to the excitation duration. Theoretical calculations suggest that the emergence of this transient ferromagnetic state is due to the imbalanced population of Mn unoccupied states caused by the Co interface.