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arXiv · 2311.04803

Coherent control of magnetization precession by double-pulse activation of effective fields from magnetoacoustics and demagnetization

M. Mattern·F. -C. Weber·D. Engel·C. Korff-Schmising·M. Bargheer
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Abstract

We demonstrate the coherent optical control of magnetization precession in a thin Ni film by a second excitation pulse which amplifies or attenuates the precession induced by a first pulse depending on the fluences of the pump-pulses and the pump-pump delay. This control goes beyond the conventional strategy, where the same mechanism drives the precession in or out-of phase. We balance the magneto-acoustic mechanism driven by quasi-static strain and the shape-anisotropy change triggered by laser-induced demagnetization. These mechanisms tilt the transient effective magnetic field in opposite directions in case of negative magneto-elastic coupling ($b_1<0$). While the strain response is linear in the fluence, demagnetization is nonlinear near the Curie temperature, enabling fluence-based control scenarios.

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M. Mattern, F. -C. Weber, D. Engel, C. Korff-Schmising, M. Bargheer. 2023-11-08. Coherent control of magnetization precession by double-pulse activation of effective fields from magnetoacoustics and demagnetization. https://arxiv.org/abs/2311.04803

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