Observation of Spontaneous Coherence in Bose-Einstein Condensate of Magnons

Journal Article · Fri Feb 01 04:00:00 EST 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.100.047205· OSTI ID:21024666

Demidov, V E; Dzyapko, O; Demokritov, S O ^[1]; Melkov, G A ^[2]; Slavin, A N ^[3]

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1. Institute for Applied Physics and Center for Nonlinear Science, University of Muenster, Corrensstrasse 2-4, 48149 Muenster (Germany)
2. Department of Radiophysics, National Taras Schevchenko University of Kiev, Kiev (Ukraine)
3. Department of Physics, Oakland University, Rochester, Michigan (United States)

The room-temperature dynamics of a magnon gas driven by short microwave pumping pulses is studied. An overpopulation of the lowest energy level of the system following the pumping is observed. Using the sensitivity of the Brillouin light scattering technique to the coherence degree of the scattering magnons we demonstrate the spontaneous emergence of coherence of the magnons at the lowest level, if their density exceeds a critical value. This finding is clear proof of the quantum nature of the observed phenomenon and direct evidence of Bose-Einstein condensation of magnons at room temperature.

• OSTI ID: 21024666
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 4 Vol. 100; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOSE-EINSTEIN CONDENSATION
ENERGY LEVELS
LIGHT SCATTERING
MAGNONS
MICROWAVE RADIATION
PULSES
PUMPING
TEMPERATURE RANGE 0273-0400 K