From Kinetic Instability to Bose-Einstein Condensation and Magnon Supercurrents
| Autor: | Kreil, Alexander J. E., Bozhko, Dmytro A., Musiienko-Shmarova, Halyna Yu., L'vov, Victor S., Pomyalov, Anna, Hillebrands, Burkard, Serga, Alexander A. |
|---|---|
| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 121, 077203 (2018) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.121.077203 |
| Popis: | Evolution of an overpopulated gas of magnons to a Bose-Einstein condensate and excitation of a magnon supercurrent, propelled by a phase gradient in the condensate wave function, can be observed at room-temperature by means of the Brillouin light scattering spectroscopy in an yttrium iron garnet material. We study these phenomena in a wide range of external magnetic fields in order to understand their properties when externally pumped magnons are transferred towards the condensed state via two distinct channels: A multistage Kolmogorov-Zakharov cascade of the weak-wave turbulence or a one-step kinetic-instability process. Our main result is that opening the kinetic instability channel leads to the formation of a much denser magnon condensate and to a stronger magnon supercurrent compared to the cascade mechanism alone. Comment: 6 pages, 3 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|