Spin Vortex in Magnon BEC of Superfluid 3He-B

TL;DR

This paper discusses the observation of magnon Bose-Einstein condensation in superfluid 3He-B, highlighting various states and spin superfluidity effects such as spin Josephson phenomena and spin current vortices.

Contribution

It reports multiple observed magnon BEC states and spin superfluidity effects in superfluid 3He-B, advancing understanding of quantum coherence in this system.

Findings

Multiple magnon BEC states observed in superfluid 3He-B

Spin superfluidity effects like Josephson phenomena demonstrated

Long-distance magnetization transport by spin supercurrents confirmed

Abstract

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.