LEXICON OF TOPOLOGICAL DEFECTS IN 3 He SUPERFLUIDS 1

Defects in the multi-dimensional macroscopic quantum field of the 3 He super-fluids are localized objects with a topological charge and are topologically stable. They include point-like objects, vortex lines, planar domain-wall-like structures, and 3-dimensional textures, which may or may not include singular points or lines. An inventory of illustrations is presented which concisely lists the different experimentally confirmed defect structures in the A and B phases of superfluid 3 He. Experimental information on defect structures in quantum fields is fragmentary and restricted by the properties and constraints of each particular degenerate many-body system in which they are studied. A notable exception are the p-wave-paired 3 He superfluids. They provide a versatile laboratory system, with a multidimensional order parameter field, in which one can study objects of different dimensionality – point defects, quantized vor-tex lines, domain-wall-like topological solitons, and 3-dim textures. Some of these, like the point defects, have not yet been directly mapped, and their role remains elusive. Others on the other hand, have helped to illustrate general principles such as composite structure and topological confinement, nucleation, and interactions between objects of different topologies. In addition to the diversity in structure, two more features have become important attributes of the current 3 He work. First, bulk superfluid 3 He is nearly devoid of extrinsic influence. The only weak heterogeneity is introduced by the surfaces of the containing vessel. Secondly, detailed theoretical understanding of the 3 He order parameter field exists [3] and can be effectively correlated with new experimental results. The latter originate to a large extent from noninvasive nuclear magnetic resonance measurement on the superfluid contained in a rotating cylinder. Similar to the application of a magnetic field on a superconductor, rotation of a superfluid is the most effective means for modifying existing