Ultrafast magnetism within time dependent density functional theory*

The search for solutions to increase the speed of manipulation of magnetic bits is a very important issue in modern information technology.
Since the outstanding discovery of the demagnetization of a Ni film by a 60 femtosecond laser pulse in 1996 several theoretical models have been proposed to explain the phenomenon.
In this work the ultrafast demagnetization of ferromagnetic clusters initiated by an optical excitation
is studied by making use of the time-dependent density functional theory. We identify the main source of spin dissipation in the process and set the stage for a quantum description of the ultrafast demagnetization in transition metals [1,2,3].

[1] M. Stamenova, J. Simoni and S. Sanvito, Role of spin orbit interaction in the ultrafast demagnetization of small iron clusters, Phys. Rev. B 94, 014423(7), (2016).
[2] J. Simoni, M. Stamenova and S. Sanvito, Ultrafast demagnetizing fields from first principles, Phys. Rev. B 95, 024412(11), (2017).
[3] J. Simoni, M. Stamenova and S. Sanvito, Ab initio dynamical exchange interactions in frustrated anti-ferromagnets, Phys. Rev. B 96, 054411(9), (2017).