Fig. 4: Comparison of experiment and theory.
From: Ultrafast opto-magnetic effects in the extreme ultraviolet spectral range
Qualitative comparison of the experimentally observed difference in demagnetization amplitudes ∆Mexp (yellow diamonds, left scale) to the difference ∆IFE (turquoise line, right scale) between the calculated opto-magnetic constants \({{{{{{\mathcal{K}}}}}}}_{{\sigma }_{\pm }}^{{{{{{\rm{IFE}}}}}}}(\omega )\) obtained from ab initio inverse Faraday effect (IFE) theory. The red circles (left scale) correspond to the output of atomistic spin dynamics (ASD) simulations, simulating the expected demagnetization difference ∆Msim induced by dichroic absorption due to the x-ray magnetic circular dichroism effect (XMCD, blue line). At 56.1 eV, two values are shown for ∆Mexp, reflecting its opposite polarity in the low vs. high fluence regime, which coincides with the steep slope of the ∆IFE spectrum at this photon energy. The error bars of ∆Msim reflect the uncertainty of the static XMCD characterization and ASD simulations, corresponding to the standard deviation of different simulation runs for a ± 0.5% variation of the input values of the XMCD magnitude. The error bars of ∆Mexp are calculated from the error propagation of the demagnetization amplitudes shown in Fig. 3.
