Spin vortex in magnon BEC of superfluid 3He–B

The phenomenon of the spontaneous 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 magnon BEC states have been observed: homogeneously precessing domain (HPD); BEC condensation in the spin–orbit potential trap (Q-balls); coherent precession with fractional magnetization; and two modes of the coherent precession in squeezed aerogel. The spin superfluidity effects, like spin Josephson phenomena, spin current vortices, spin phase slippage, long distance magnetization transport by spin supercurrents have been observed.