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arXiv · 2101.07890

Evolution of room-temperature magnon gas toward coherent Bose-Einstein condensate

Timo B. Noack·Vitaliy I. Vasyuchka·Anna Pomyalov·Victor S. L'vov·Alexander A. Serga·Burkard Hillebrands
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Abstract

The appearance of spontaneous coherence is a fundamental feature of a Bose-Einstein condensate and an essential requirement for possible applications of the condensates for data processing and quantum computing. In the case of a magnon condensate in a magnetic crystal, such computing can be performed even at room temperature. So far, the process of coherence formation in a magnon condensate was inaccessible. We study the evolution of magnon radiation spectra by direct detection of microwave radiation emitted by magnons in a parametrically driven yttrium iron garnet crystal. By using specially shaped bulk samples, we show that the parametrically overpopulated magnon gas evolves to a state, whose coherence is only limited by the natural magnon relaxation into the crystal lattice.

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Timo B. Noack, Vitaliy I. Vasyuchka, Anna Pomyalov, Victor S. L'vov, Alexander A. Serga, Burkard Hillebrands. 2021-01-19. Evolution of room-temperature magnon gas toward coherent Bose-Einstein condensate. https://doi.org/10.1103/physrevb.104.l100410

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