At the frontier between ultrafast optics and magnetism

Femtomagnetism is a research field that combines magnetism and optics, using femtosecond laser pulses. The main goals are to explore the fundamental mechanisms occurring after short light pulses interact either with electronic spins in condensed phase systems like ferromagnetic metals or with isolated spins. The outcomes are important in several application sectors such as fast recording in magnetic media, magneto-optical sensors, picosecond magneto-acoustics, spintronic systems controlled optically. This lecture reviews several aspects of Femtomagnetism starting from elementary concepts of light matter interaction in magnetic systems. These concepts are used to exemplify a variety of dynamical processes such as the time dependent heating of spins to the Curie temperature, the precession and damping of the magnetization, the coupling between acoustic pulses and spins or the temporal regime of coherent spin-photon interaction.