Dresden 2014 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 55: Poster II

MA 55.2: Poster

Freitag, 4. April 2014, 10:30–13:30, P2

Magnon Bose Einstein Condensate moving in real space — •Patryk Nowik-Boltyk, Oleksandr Dzyapko, Vladislav E. Demidov, and Sergej O. Demokritov — Institute of Applied Physics, University of Muenster, Muenster, Germany

Magnon Bose-Einstein condensation, created by microwave pumping in Yttrium-Iron-Garnet films, is a spectacular room-temperature macroscopic quantum phenomenon, which is under extended investigation since recently [1]. Temporal [2] and spatial [3] coherence of the condensate have extensively been studied in the past 5 years. As a mBEC is located at the ground state of the magnon system its group velocity is zero, therefore the condensate is not moving in real space and occupies the same area are for a long time if kept in flow equilibrium. We demonstrate a way to create a moving condensate by applying a pulsed magnetic field localized in real space. As a result of the pulsed field the condensate gains a group velocity that is determined by the amplitude of the localized magnetic field. The space, time and frequency dependent magnon density has been determined using a space, time and frequency resolved Brillouin light scattering technique. [1] S.O. Demokritov et al. Nature 443, 430 (2006) [2] V.E. Demidov et al. Phys. Rev. Lett. 100, 047205 (2008) [3] P. Nowik-Boltyk et al. Nature Sci. Rep. 2, 482 (2012)