Weder, DavidKorff Schmising, Clemens vonGünther, Christian MichaelSchneider, MichaelEngel, DieterHessing, P.Struber, ChristianWeigand, M.Vodungbo, B.Jan, EmmanuelleLiu, X.Merhe, Alaa el dinePedersoli, EmanueleCapotondi, FlavioLüning, J.Pfau, BastianEisebitt, Stefan2021-11-222021-11-222020-09-08https://depositonce.tu-berlin.de/handle/11303/13926http://dx.doi.org/10.14279/depositonce-12700Laser-driven non-local electron dynamics in ultrathin magnetic samples on a sub-10 nm length scale is a key process in ultrafast magnetism. However, the experimental access has been challenging due to the nanoscopic and femtosecond nature of such transport processes. Here, we present a scattering-based experiment relying on a laser-induced electro- and magneto-optical grating in a Co/Pd ferromagnetic multilayer as a new technique to investigate non-local magnetization dynamics on nanometer length and femtosecond timescales. We induce a spatially modulated excitation pattern using tailored Al near-field masks with varying periodicities on a nanometer length scale and measure the first four diffraction orders in an x-ray scattering experiment with magnetic circular dichroism contrast at the free-electron laser facility FERMI, Trieste. The design of the periodic excitation mask leads to a strongly enhanced and characteristic transient scattering response allowing for sub-wavelength in-plane sensitivity for magnetic structures. In conjunction with scattering simulations, the experiment allows us to infer that a potential ultrafast lateral expansion of the initially excited regions of the magnetic film mediated by hot-electron transport and spin transport remains confined to below three nanometers.en530 Physikoptical propertiesscattering problemFourier analysiselectronic transportfree electron lasersmagnetic circular dichroism spectroscopyX-ray scatteringmagnetization dynamicstransport propertiesArticle2329-777832923511