Berlin 2024 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 20: Poster I
MA 20.6: Poster
Dienstag, 19. März 2024, 16:30–19:00, Poster A
Dynamics of magnon condensates in two-dimensional thermal landscapes — •Franziska Kühn1, Matthias R. Schweizer1, Georg von Freymann1,2, Alexander A. Serga1, and Burkard Hillebrands1 — 1Fachbereich Physik and Landesforschungszentrum OPTIMAS, RPTU Kaiserslautern-Landau, 67663 Kaiserslautern, Germany — 2Fraunhofer Institute for Industrial Mathematics ITWM, Fraunhofer Platz 1, 67663 Kaiserslautern, Germany
Our work focuses on the behavior of magnon Bose-Einstein condensates (BEC) in two-dimensional artificial magnetization landscapes on the length scale of the wavelength of condensed magnons. Measurements are performed using Brillouin light scattering spectroscopy as an optical detection method of magnons. In addition, different thermal patterns in the micrometer range are imprinted onto the yttrium-iron garnet film sample through phase-based wavefront modulation. This procedure changes the temperature-dependent saturation magnetization and subsequently the effective magnetic field. Both of these effects influence the magnon spectrum to varying degrees and cause strong frequency shifts in the dispersion relation. The corresponding spatial variation of the condensate frequency, acting as an artificial potential for the BEC, affects its dynamics and propels magnon supercurrents and Bogoliubov waves. Extended two-dimensional structures are used to investigate the manipulation of the properties of magnon supercurrents, such as direction and intensity. This research was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)-TRR 173/2-268565370 Spin+X (Project B04)
Keywords: Spin Waves; Magnon Condensate; Temperature Landscapes; Supercurrents; Brillouin Light Scattering Spectroscopy