Time. Friday, October 26th, 9:00
Speaker: Martin WEINELT, Berlin
On which timescale do the electronic band structure and spin polarization of a ferromagnet change after femtosecond laser excitation and how do they react to spin transport and spin-flip scattering?
To answer these questionswe perform time-, spin-, and angle-resolved photoemission experiments with optical laser pulses and higher-order harmonic radiation and investigate the transient magnetization by time-resolved X-ray magnetic circular dichroism in reflection.
For the local ferromagnets gadolinium and terbium and their combination in bilayers, we show that exchange splitting, spin polarization, and transient magnetic moment can respond on significantly different timescales. This allows us to distinguish between contributions of spin-flip scattering, spin-lattice coupling, and spin transport to the ultrafast magnetization dynamics.