Observation of combined spin-mass vortices in rotating 3B

We have observed spin-mass vortices (SMV) in rotating superfluid 3B. The SMV is a combined topological object formed of an ordinary vortex with mass current and of a disclination with spin current. A planar defect, so-called θ soliton, is topologically bound to the SMV line. The SMV’s were created primarily by cooling the 3He sample through a reversible A→B transition at a constant rotation velocity, which was smaller than the critical velocity for the nucleation of vortices in3He-B. The observation of the SMV’s is based on changes in the NMR absorption caused by the attached solitons: The absorption is shifted to higher frequencies in conventional NMR at low rf excitation and large additional absorption is observed in the homogeneously precessing domain (HPD) at high excitation. The presence of SMV’s is deduced from the stability and from the rotation-speed dependence of the additional absorption.