Speaker
Leonard Müller
(DESY)
Description
Free-electron laser (FEL) sources based on self-amplified spontaneous emission can provide intense and ultra short femtosecond x-ray pulses from the vacuum ultraviolet to the x-ray range. The unique combination of short pulselength and short wavelength allows to investigate a number of dynamic phenomena on otherwise inaccessible scales.
One of the forefront problems in modern magnetism research, namely ultra-fast demagnetization, related to non-equilibrium magnetization dynamics and manipulation of the magnetic state on ultra-fast time scales, can be addressed with the possibilities of these new sources [C. Gutt, et al., PRB, 79 212406 (2009), C. Gutt, et al., PRB 81, 100401(R) (2010).]. Here results of an optical IR-pump–FEL-probe experiment on a ferromagnetic Co/Pt multilayer with perpendicular magnetic anisotropy are shown. The optically induced ultra-fast demagnetization dynamics have been measured with resonant x-ray small angle scattering element specific at the Co M-edge allowing for simultaneous observation of the local magnetization and the characteristic length scale of the domains via the x-ray magnetic circular dichroism (XMCD) effect.
The experiments were performed at the FLASH facility at DESY in Hamburg.
Authors
Christian Gutt
(DESY)
Gerhard Grübel
(DESY)
Hans-Peter Oepen
(Universität Hamburg)
Jan Lüning
(University Pierre et Marie Curie)
Leonard Müller
(DESY)
Stefan Eisebitt
(Technische Universität Berlin)
Co-authors
André Kobs
(Universität Hamburg)
Boris Vodungbo
(University Pierre et Marie Curie)
Daniel Sticker
(Universität Hamburg)
Felix Büttner
(Technische Universität Berlin)
Jan Geilhufe
(Technische Universität Berlin)
Jyoti Mohanty
(Technische Universität Berlin)
Matthias Hille
(Universität Hamburg)
Robert Frömter
(Universität Hamburg)
Stefan Heinze
(Technische Universität Berlin)
William F. Schlotter
(SLAC/LCLS)
