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arXiv · 1208.1462

Observation of Coherent Helimagnons and Gilbert damping in an Itinerant Magnet

J. D. Koralek·D. Meier·J. P. Hinton·A. Bauer·S. A. Parameswaran·A. Vishwanath·R. Ramesh·R. W. Schoenlein·C. Pfleiderer·J. Orenstein
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Abstract

We study the magnetic excitations of itinerant helimagnets by applying time-resolved optical spectroscopy to Fe0.8Co0.2Si. Optically excited oscillations of the magnetization in the helical state are found to disperse to lower frequency as the applied magnetic field is increased; the fingerprint of collective modes unique to helimagnets, known as helimagnons. The use of time-resolved spectroscopy allows us to address the fundamental magnetic relaxation processes by directly measuring the Gilbert damping, revealing the versatility of spin dynamics in chiral magnets. (*These authors contributed equally to this work)

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J. D. Koralek, D. Meier, J. P. Hinton, A. Bauer, S. A. Parameswaran, A. Vishwanath, R. Ramesh, R. W. Schoenlein, C. Pfleiderer, J. Orenstein. 2012-08-07. Observation of Coherent Helimagnons and Gilbert damping in an Itinerant Magnet. https://doi.org/10.1103/physrevlett.109.247204

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