arXiv subjects
Publications and source records attributed to Niko Pontius.
Due to an error this article has been annouced as a new article instead of a corrected version of article 1010.1374.
Femtosecond x-ray magnetic circular dichroism was used to study the time-dependent magnetic moment of 4 fs electrons in the ferromagnets Gd and Tb, which are known for their different spin-lattice coupling. We observe a two-step demagnetization with an ultrafast demagnetization time of 750 fs identical for both systems and slower times which differ sizeably with 40 ps for Gd and 8 ps for Tb. We conclude that spin-lattice coupling in the electronically excited state is enhanced up to orders of magnitude compared to equilibrium.