The manipulation of material properties on the timescale shorter than subpicoseconds paves the way for the observation of new phenomena, such as strongly nonlinear responses and instantaneous photoinduced phase transitions. From the perspective of magnetism, this represents a promising approach to accelerating the response speed of magnetic moments compared to traditional electrical methods. This could enable the realization of next-generation spin devices based on antiferromagnets, materials with antiparallel spin order, which exhibit a faster response in the terahertz frequency range compared to that of ferromagnets. We investigated antiferromagnetic spin dynamics driven by various laser sources with photon energies spanning from the visible to the farinfrared spectral regions.
Yuichi Saito (Thu,) studied this question.