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arXiv · 1502.03963

Bose-Einstein condensation of magnons in atomic hydrogen gas

O. Vainio·J. Ahokas·J. Järvinen·L. Lehtonen·S. Novotny·S. Sheludiakov·K. -A. Suominen·S. Vasiliev·D. Zvezdov·V. V. Khmelenko·D. M. Lee
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Abstract

We report on experimental observation of BEC-like behaviour of quantized electron spin waves (magnons) in a dense gas of spin polarized atomic hydrogen. The magnons are trapped and controlled with inhomogeneous magnetic fields, and described by a Schrödinger-like wave equation, in analogy to the BEC experiments with neutral atoms. We have observed the appearance of a sharp feature in the ESR spectrum displaced from the normal spin wave spectrum. We believe that this observation corresponds to a sudden growth of the ground state population of the magnons and emergence of their spontaneous coherence for hydrogen gas densities exceeding a critical value, dependent on the trapping potential. We interpret the results as a BEC of non-equilibrium magnons which were formed by applying the rf power.

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O. Vainio, J. Ahokas, J. Järvinen, L. Lehtonen, S. Novotny, S. Sheludiakov, K. -A. Suominen, S. Vasiliev, D. Zvezdov, V. V. Khmelenko, D. M. Lee. 2015-02-13. Bose-Einstein condensation of magnons in atomic hydrogen gas. https://doi.org/10.1103/physrevlett.114.125304

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