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Title: Spin wavepackets in the Kagome ferromagnet Fe 3 Sn 2 : Propagation and precursors

The propagation of spin waves in magnetically ordered systems has emerged as a potential means to shuttle quantum information over large distances. Conventionally, the arrival time of a spin wavepacket at a distance,d, is assumed to be determined by its group velocity,vg. Here, we report time-resolved optical measurements of wavepacket propagation in the Kagome ferromagnet Fe3Sn2that demonstrate the arrival of spin information at times significantly less thand/vg. We show that this spin wave “precursor” originates from the interaction of light with the unusual spectrum of magnetostatic modes in Fe3Sn2. Related effects may have far-reaching consequences toward realizing long-range, ultrafast spin wave transport in both ferromagnetic and antiferromagnetic systems.

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Proceedings of the National Academy of Sciences
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Proceedings of the National Academy of Sciences
Medium: X
Sponsoring Org:
National Science Foundation
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