title: Bose-Einstein condensation of magnons in atomic hydrogen gas.
abstract: We report on experimental observation of Bose-Einstein condensation (BEC)-like behavior 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 nonequilibrium magnons which were formed by applying the rf power.
authors: Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland.
authors: O
authors: O
authors: Vainio
authors: Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland.
authors: J
authors: J
authors: Ahokas
authors: Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland.
authors: J
authors: J
authors: Järvinen
authors: Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland.
authors: L
authors: L
authors: Lehtonen
authors: Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland.
authors: S
authors: S
authors: Novotny
authors: Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland.
authors: S
authors: S
authors: Sheludiakov
authors: Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland.
authors: K-A
authors: KA
authors: Suominen
authors: Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland.
authors: S
authors: S
authors: Vasiliev
authors: Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland.|Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russia.
authors: D
authors: D
authors: Zvezdov
authors: Department of Physics and Astronomy and Institute for Quantum Science and Engineering, Texas A&M University, College Station, Texas 77843, USA.
authors: V V
authors: VV
authors: Khmelenko
authors: Department of Physics and Astronomy and Institute for Quantum Science and Engineering, Texas A&M University, College Station, Texas 77843, USA.
authors: D M
authors: DM
authors: Lee