Regensburg 2019 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 8: Magnonics

MA 8.14: Vortrag

Montag, 1. April 2019, 18:30–18:45, H52

Temporal evolution of magnon-magnonen interactions in a magnetic vortex — •Tobias Hula¹, Katrin Schultheiß¹, Lukas Körber^{1, 2}, Franziska Wehrmann¹, Kai Wagner¹, and Helmut Schultheiß^{1, 2} — ¹Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany — ²Technische Universität Dresden, 01062 Dresden, Germany

Brillouin light scattering microscopy measurements on a Permalloy disk magnetized in the vortex state are presented. By applying a homogenous out-of-plane AC field with sufficiently large amplitudes it is possible to drive the spin waves in the nonlinear regime and initiate three- and four-magnon scattering processes.

Time resolved BLS microscopy is used to show that these pumping conditions cause cascades of different types of magnon-magnon interactions. It is shown, that the temporal transition of different scattering mechanisms can be tuned by the excitation frequency and amplitude.

Further, an experimental approach to determine the coupling between directly excited magnons and magnons excited via nonlinear scattering is presented. To rule out unknown parameters like lifetime and thermal population, tr-BLS measurements with two RF sources where performed.