Laser-driven nanoscale magnetization dynamics: A perspective on the modification of domains at femtosecond timescales

In this Perspective, we present an overview of the ultrafast dynamics of magnetic domains driven by laser excitation at femtosecond timescales. The review surveys the current landscape of research and highlights key contributions to the field. We focus on the modification of nanoscale magnetic domain patterns following laser excitation, studied using x-ray free-electron laser (XFEL) sources and high-harmonic generation (HHG). Measurements performed by different research groups have shown magnetization dynamics that are dependent on magnetic domain type, where distortions in the diffraction patterns for labyrinth-type domains have been a source of controversy in the field. On the other hand, stripe domains show a different response, clearly indicating that nanoscale effects need to be included in explaining ultrafast magnetization dynamics. With upcoming time-resolved imaging techniques emerging at XFEL and HHG sources, direct experimental results are now within reach to further clarify the mechanisms behind the ultrafast modification of domain patterns.