Dresden 2020 – wissenschaftliches Programm
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MA 53.5: Vortrag
Donnerstag, 19. März 2020, 16:00–16:15, HSZ 401
Room-temperature magnon Josephson oscillations — •Alexander J. E. Kreil1, Anna Pomyalov2, Victor S. L’vov2, Halyna Yu. Musiienko-Shmarova1, Gennadii A. Melkov3, Alexander A. Serga1, and Burkard Hillebrands1 — 1Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany — 2Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 76100, Israel — 3Faculty of Radiophysics, Electronics and Computer Systems, Taras Shevchenko National University of Kyiv, Kyiv 01601, Ukraine
The alternating current (ac) Josephson effect is known as a rapidly oscillating current, which appears between weakly coupled macroscopic quantum states, such as superconducting states subject to an external dc voltage. So far, this phenomenon was observed at cryogenic temperatures in superconductors, in superfluid helium, and in Bose-Einstein condensates (BECs) of trapped atoms. A similar effect is expected in a magnon BEC at room-temperature. Here, we report on the experimental discovery of the ac Josephson effect in a magnon BEC carried by a room-temperature ferrimagnetic film. We suggest a theoretical model that adequately describes the observed supercurrent flow, which itself manifests as oscillations in the magnon BEC density and supports the findings.