Regensburg 2019 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 15: Magnetism Poster A

MA 15.39: Poster

Dienstag, 2. April 2019, 10:00–13:00, Poster E

Two-dimensional magnon supercurrents — •Alexander J. E. Kreil, Dmytro A. Bozhko, Alexander A. Serga, and Burkard Hillebrands — Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany

Earlier, we reported on supercurrent transport of a room-temperature magnon Bose-Einstein condensate (BEC) observed in yttrium iron garnet films by means of time- and space-resolved Brillouin light scattering spectroscopy (BLS) [1-3]. By locally heating the sample, a spatially variation of the saturation magnetization was induced, which lead to a magnon supercurrent flowing out of the heated spot. The condensed magnons being propelled out of the heated area formed compact humps of BEC density, which propagated many hundreds of micrometers in the form of second sound Bogoliubov waves. Our theoretical estimations predict a strong anisotropy in the propagation characteristics of the magnon supercurrents. In the current work, we show the results of a two-dimensional spatially resolved BLS probing the magnon BEC formed in a magnetically non-uniform sample and compare the experimental data with theoretical estimations. =-1

[1] D.A. Bozhko et al., Supercurrent in a room temperature Bose-Einstein magnon condensate, Nat. Phys. 12, 1057 (2016).

[2] A.J.E. Kreil et al., From kinetic instability to Bose-Einstein condensation and magnon supercurrents, PRL 121, 077203 (2018).

[3] D.A. Bozhko et al., Long-distance supercurrent transport in a room-temperature Bose-Einstein magnon condensate, arXiv:1808.07407.