Vortices in Rotating Superfluid 3He

Four different types of vortices andone metastable vortex statehave been observed in the rotating superfluid 3He. In the A-phase, both continuous vortices with two circulation quanta and singular vorticeswith one circulation quantumhavebeen identified. The rotating B-phase displays two regions in the pT-planewithdifferent stable vortex structures separated by a first order phasetransition. A metastable vortex state is obtained when cooling, during rotation, through the first order phase transition line. The relevant experimental data for these identifications are reviewed and their interpretation is discussed on the basis ofthe present theoretical understanding.