Faster chiral magnetic order recovery

Studying the ultafast dynamics of chiral spin structures (Skyrmions) stabilized by Dzyaloshinskii-Moriya interaction (DMI) after optical excitation, the observed recovery of the chiral magnetic order is faster than the average collinear domain magnetization.

Kerber et al., Nature Communications, Vol. 11 - 1, pp. 6304 (2020).
 

Faster chiral versus collinear magnetic order recovery

After an ultrafast optical pulse, magnetic small angle scattering is measured in reflection for both right and left circularly polarized XUV ultrafast FEL pulses, tuned to 23.0 nm at the Fe M2,3 dichroic transition to maximize the X-ray magnetic circular dichroism (XMCD) effect.

The sum and the difference of the images acquired with opposite polarizations represent the total ferromagnetic order and the chiral order respectively. An increase of the width of the structure factor peak is detected only for the collinear signal, while the chiral scattering peak does not increase and shows a faster recovery.

This is explained with the onset of strong transversal magnetic fluctuations after pumping in the domain systems, that are reduced within the chiral domain walls, leading to a chiral order that is restored faster.

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Faster chiral versus collinear magnetic order recovery after optical excitation revealed by femtosecond XUV scattering.

N. Kerber, D. Ksenzov, F. Freimuth, F. Capotondi, E. Pedersoli, I. Lopez-Quintas, B. Seng, J. Cramer, K. Litzius, D. Lacour, H. Zabel, Y. Mokrousov, M. Kläui, C. Gutt.

Nature Communications, Vol. 11 - 1, pp. 6304 (2020).

DOI: 10.1038/s41467-020-19613-z

Ultima modifica il Mercoledì, 09 Dicembre 2020 19:18