Distinct Ultrafast Electronic and Magnetic Response in M-edge Magnetic Circular Dichroism

Abstract

Experimental investigations of ultrafast magnetization dynamics increasingly employ resonant magnetic spectroscopy in the ultraviolet spectral range. Besides allowing to disentangle the element-specific transient response of functional magnetic systems, these techniques also promise to access attosecond to few-femtosecond dynamics of spin excitations. Here, we report on a systematic study of transient magnetic circular dichroism (MCD) on the transition metals Fe, Co and Ni as well as on a FeNi and GdFe alloy and reveal a delayed onset between the electronic and magnetic response. Supported by \textit{ab-initio} calculations, we attribute our observation to a transient energy shift of the absorption and MCD spectra at the corresponding elemental resonances due to non-equilibrium changes of electron occupations.

8 figures

References in corpus (2)

• Influence of laser-excited electron distributions on the x-ray magnetic circular dichroism spectra: Implications for femtosecond demagnetization in Ni
• Magneto-Optical Functions at the 3p resonances of Fe, Co, and Ni: Ab-initio description and experiment

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