Biplab Sanyal: Ultrafast demagnetization dynamics of amorphous FeGd alloys from first principles theory
|Wanneer:||do 13-07-2017 11:00 - 12:00|
Laser induced ultrafast magnetization dynamics in the femtosecond time scale has created a lot of attention due to its potential in realizing all-optical magnetic switching in a fast and efficient way. However, the fundamental understanding of magnetization dynamics is yet to reach a high level of acceptance due to the intricate interplay of electron, lattice and spin degrees of freedom under intense laser pulse. In this talk, I will demonstrate a multiscale approach to study ultrafast magnetization dynamics by combining ab initio density functional theory, atomistic spin dynamics utilizing Landau-Lifshitz-Gilbert equation of motion and phenomenological models. Different characteristics of sublattice magnetization dynamics in amorphous FeGd alloys will be discussed from the point of view of local chemical inhomogeneity giving rise to frustration in magnetic exchange and spin-orbit coupling induced anisotropic exchange. The results will be used to explain recent experimental findings.