Observation of coherent helimagnons and gilbert damping in an itinerant magnet
Koralek, J.D., D. Meier, J.P. Hinton, A. Bauer, S.A. Parameswaran, A. Vishwanath, Ramamoorthy Ramesh, R.W. Schoenlein, C. Pfleiderer, J. Orenstein
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 "format"to address the fundamental magnetic relaxation processes by directly measuring the Gilbert damping, revealing the versatility of spin dynamics in chiral magnets. © 2012 American Physical Society.
Physical Review Letters
Year of Publication