Magnon condensation into Q-ball in 3He-B

Abstract

The theoretical prediction of Q-balls in relativistic quantum fields is realized here experimentally in superfluid 3He-B. The condensed-matter analogs of relativistic Q-balls are responsible for an extremely long lived signal of magnetic induction -- the so-called Persistent Signal -- observed in NMR at the lowest temperatures. This Q-ball is another representative of a state with phase coherent precession of nuclear spins in 3He-B, similar to the well known Homogeneously Precessing Domain which we interpret as Bose condensation of spin waves -- magnons. At large Q the effect of self-localization is observed. In the language of relativistic quantum fields it is caused by interaction between the charged and neutral fields, where the neutral field provides the potential for the charged one. In the process of self-localization the charged field modifies locally the neutral field so that the potential well is formed in which the charge is condensed.

4 pages, 3 figures, submitted to PRL, modified after referee report

References in corpus (2)

• Solution of the problem of catastrophic relaxation of homogeneous spin precession in superfluid ${}^3$He-B
• On the problem of catastrophic relaxation in superfluid 3-He-B

Cited by in corpus (11)

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• Spontaneous rotating vortex lattices in a pumped decaying condensate
• On Larkin-Imry-Ma State of 3He-A in Aerogel
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• Strong orientational effect of stretched aerogel on the 3He order parameter
• Twenty years of magnon Bose condensation and spin current superfluidity in 3He-B
• Compact Q-balls in the complex signum-Gordon model
• Observation of Coherent Precession of Magnetization in Superfluid 3He A-phase
• Spin echo in spinor dipolar Bose-Einstein condensates
• Spin Vortex in Magnon BEC of Superfluid 3He-B
• Stationary Precession Topological Solitons with Nonzero Hopf Invariant in a Uniaxial Ferromagnet