English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Ultrafast phenomena on a femtosecond timescale are commonly examined bypump-probe experiments. This implies multiple measurements where the sampleunder investigation is pumped with a short light pulse and then probed with asecond pulse at various time delays to follow its dynamics. Recently, theprinciple of streaking extreme ultraviolet (XUV) pulses in the temporal domainhas enabled recording the dynamics of a system within a single pulse. However,separate pump-probe experiments at different absorption edges still lack aunified timing, when comparing the dynamics in complex systems. Here we reporton an experiment using a dedicated optical element and the two-color emissionof the FERMI XUV free-electron laser to follow the charge and spin dynamics incomposite materials at two distinct absorption edges, simultaneously. Thesample, consisting of ferromagnetic Fe and Ni layers, separated by a Cu layer,is pumped by an infrared laser and probed by a two-color XUV pulse with photonenergies tuned to the M edges of these two transition metals. The experimentalgeometry intrinsically avoids any timing uncertainty between the two elementsand unambiguously reveals an approximately 100 fs delay of the magneticresponse with respect to the electronic excitation for both Fe and Ni. Thisdelay shows that the electronic and spin degrees of freedom are decoupledduring the demagnetization process. These observations underline the importanceof simultaneous investigation of the temporal response of both charge and spinin multi-component materials. In a more general scenario, the experimentalapproach can be extended to continuous energy ranges, promising the developmentof jitter-free transient absorption spectroscopy in the XUV and soft X-rayregimes.

Simultaneous two-color snapshot view on ultrafast charge and spin dynamics in a Fe-Cu-Ni tri-layer