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arXiv · 2410.19263

Ultrafast selective mid-infrared sublattice manipulation in the ferrimagnet $FeCr_2S_4$

Davide Soranzio·Matteo Savoini·Fabian Graf·Rafael T. Winkler·Abhishek Nag·Hiroki Ueda·Kenya Ohgushi·Yoshinori Tokura·Steven L. Johnson
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Abstract

$FeCr_2S_4$ is a ferrimagnet with two oppositely ordered spin sublattices (Fe and Cr), connected via superexchange interaction, giving a non-zero net magnetic moment. We show, using time-resolved measurements of the magneto-optic Kerr effect, how the magnetic dynamics of the sublattices can be selectively manipulated by resonantly perturbing the Fe sublattice with ultrashort laser pulses. The mid-infrared excitation through intra-atomic Fe $d$-$d$ transitions triggers markedly slower dynamics in comparison to an off-resonant pumping affecting both of the two sublattices simultaneously. By changing probe wavelength to move in and out of resonance with the Fe $d$-$d$ transitions, we also show the specific contributions of the Fe sublattice to these dynamics.

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Davide Soranzio, Matteo Savoini, Fabian Graf, Rafael T. Winkler, Abhishek Nag, Hiroki Ueda, Kenya Ohgushi, Yoshinori Tokura, Steven L. Johnson. 2024-10-25. Ultrafast selective mid-infrared sublattice manipulation in the ferrimagnet $FeCr_2S_4$. https://doi.org/10.1103/zn5y-vgkw

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