Grand Séminaire d'Institut

Vendredi 7 Juillet 2017 à 11h00.

Ultrafast demagnetization and angular momentum transfer in Ferromagnetic Transition Metals

''Ultrafast demagnetization and angular momentum transfer in Ferromagnetic Transition Metals Exact calculated time evolutions in the framework of a many-electron model of itinerant magnetism provide new insights into the laser-induced ultrafast demagnetization observed in ferromagnetic (FM) transition metal thin films. The interplay between local spin-orbit interactions and interatomic hopping is shown to be at the origin of the observed postexcitation breakdown of FM correlations between highly stable local magnetic moments. The mechanism behind spin- and angular-momentum transfer is revealed from a microscopic perspective by rigorously complying with all fundamental conservation laws. An energy-resolved analysis of the time evolution shows that the efficiency of the demagnetization process reaches almost 100% in the excited states.''