2015, S. Autti, V.V. Dmitriev, V.B. Eltsov, J. Makinen, G.E. Volovik, A.N. Yudin, V.V. Zavjalov, “Observation of half-quantum vortices in superfluid 3He”, in arXiv:
Experiments also demonstrate that the HQVs formed under rotation are strongly pinned by the nafen strands..