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arXiv · 1010.1374

Hot electron driven enhancement of spin-lattice coupling in 4f ferromagnets observed by femtosecond x-ray magnetic circular dichroism

Marko Wietstruk·Alexey Melnikov·Christian Stamm·Torsten Kachel·Niko Pontius·Muhammad Sultan·Cornelius Gahl·Martin Weinelt·Hermann A. Dürr·Uwe Bovensiepen
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Abstract

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.

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Marko Wietstruk, Alexey Melnikov, Christian Stamm, Torsten Kachel, Niko Pontius, Muhammad Sultan, Cornelius Gahl, Martin Weinelt, Hermann A. Dürr, Uwe Bovensiepen. 2011-01-07. Hot electron driven enhancement of spin-lattice coupling in 4f ferromagnets observed by femtosecond x-ray magnetic circular dichroism. https://doi.org/10.1103/physrevlett.106.127401

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