Regensburg 2016 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 52: Focus: Ultrafast spin currents for spin-orbitronics: from metals to topological insulators

MA 52.3: Hauptvortrag

Freitag, 11. März 2016, 10:45–11:15, H32

Real-time time-dependent DFT for spin dynamics in magnets — •Stefano Sanvito, Maria Stamenova, and Jacopo Simoni — School of Physics and CRANN, Trinity College, Dublin 2, Ireland

Ultra-fast laser-driven spin dynamics is rapidly becoming a tool to manipulate the magnetic interaction at the femtosecond timescale. In this limit both the magnetic exchange and the anisotropy become time-dependent and the modelling of the spin-dynamics must be carried out at the electronic level. Here we show how real time time-dependent density functional theory can be used to understand the first femtoseconds of the laser-induced spin dynamics of magnetic transition metals. In particular we will present the case of both finite magnetic clusters and bulk transition metals. We will show how the demagnetisation immediately following the laser excitation is uniquely driven by the strength of the spin-orbit interaction, and how it relates to oscillations of the charge density between the core and the interstitial regions. Furthermore, we will demonstrate how such rapid demagnetisation is affected by the laser intensity and polarisation, and how it scales with the size of the system under investigation.