Bose-Einstein condensation of magnons in superfluid 3He
Abstract
The possibility of Bose-Einstein condensation of excitations has been discussed for a long time. The phenomenon of the phase-coherent precession of magnetization in superfluid 3He and the related effects of spin superfluidity are based on the true Bose-Einstein condensation of magnons. Several different states of coherent precession has been observed in 3He-B: homogeneously precessing domain (HPD); persistent signal formed by Q-balls at very low temperatures; coherent precession with fractional magnetization; and two new modes of the coherent precession in compressed aerogel. In compressed aerogel the coherent precession has been also found in 3He-A. Here we demonstrate that all these cases are examples of a Bose-Einstein condensation of magnons, with the magnon interaction term in the Gross-Pitaevskii equation being provided by different types of spin-orbit coupling in the background of the coherent precession.
Keywords
Cite
@article{arxiv.0708.0663,
title = {Bose-Einstein condensation of magnons in superfluid 3He},
author = {Yu. M. Bunkov and G. E. Volovik},
journal= {arXiv preprint arXiv:0708.0663},
year = {2009}
}
Comments
10 pages, 5 figures, prepared for proceedings of QFS-2007, JLTP style