Phonons in magnon superfluid and symmetry breaking field
G. E. Volovik
Low Temperature Laboratory, Helsinki University of Technology, FIN-02015 HUT, Finland
Landau Institute for Theoretical Physics RAS, 119334 Moscow, Russia
PACS: 03.75.Kk, 47.37.+q, 67.30.Hj
Abstract
Recent experiments [11volov-PhononMass,11volov-Skyba] which measured
the spectrum of the Goldstone collective mode of coherently precessing state
in 3He-B are discussed using the presentation of the coherent spin
precession in terms of the Bose-Einstein condensation of magnons. The mass in
the spectrum of the Goldstone boson - phonon in the superfluid magnon
liquid - is induced by the symmetry breaking field, which is played by the
RF magnetic field.