Observation of half-quantum defects in superfluid 3He-B -: art. no. 210402

In the course of high-precision measurements of the relation between the superflow current J through a weak link in He-3-B and the difference in order parameter phase between each side of the link Phi in a flexible wall Helmholtz resonator equipped with a rotation pickup loop, we have observed the signature of a stable textural defect that sustains a change of the phase by pi across it. Cosmiclike solitons, proposed by Salomaa and Volovik and hitherto thought unstable, can constitute such a defect.